Ukrainian engineers say they worked 35 days straight on minimal sleep in order to keep Chernobyl nuclear power plant safe while Russian soldiers controlled the site.
Catch up on Wednesday's events with our live blog.
Key events
- Chernobyl's engineers tell tale of Russian occupation
- Russia gives Ukrainian fighters in Mariupol a fresh ultimatum
- Russia's Defence Minister accuses Western nations of doing all they can to drag out Russia’s invasion
- Vladimir Putin awards military honour to unit accused of Bucha war crimes
- UN Secretary-General calls for a four-day halt in fighting for Easter
- US to announce another military aid package for Ukraine
- Ukraine says Russian forces have captured a frontline city
Live updates
By Jacqueline Howard
That's all for the blog today
Thanks for following along throughout the day.
You can stay up-to-date with the latest news online or on the ABC News app.
By Jacqueline Howard
Timeframe for Mariupol evacuation
Ukraine's Deputy Prime Minister Iryna Vereshchuk says the attempted evacuation of women, children and the elderly from Mariupol would start at 2pm local time (9pm AEST)
"Given the very difficult security situation, changes may occur during the corridor action. So, please follow the relevant official messages," she said.
Mayor Vadym Boichenko, who has left Mariupol, said he hoped a preliminary agreement with Russia on establishing a safe corridor would be firmed up and hold.
He said he hoped around 6,000 people would leave the city. He believes about 100,000 civilians remain in Mariupol.
Local authorities say thousands of people have been killed in the siege of Mariupol and that the port city on the Sea of Azov has been all but destroyed.
A previous agreement to create a humanitarian corridor for civilians to leave Mariupol collapsed on March 5. Since then, repeated efforts to create a safe corridor have failed, with each side blaming the other.
By Jacqueline Howard
Ukraine says preliminary agreement reached on evacuating women, children and old people from Mariupol
Ukraine has reached a preliminary agreement with Russia on establishing a humanitarian corridor to evacuate women, children and the elderly from Mariupol on Wednesday, Ukrainian Deputy Prime Minister Iryna Vereshchuk said.
"Given the catastrophic humanitarian situation in Mariupol, this is where we will focus our efforts today," she wrote on Facebook.
By Jacqueline Howard
Japan formally revokes Russia's 'most favoured nation' status
Japan formally revoked Russia as its “most favoured nation” to trade with on Wednesday.
The stripping of Russia’s trade status is Japan's latest move against Moscow and was part of a list of sanctions measures Prime Minister Fumio Kishida announced last month that also included a decision to expel eight Russian diplomats and trade officials.
Japan has also frozen the assets of hundreds of Russian individuals and groups and banned new investment and trade, including the export of goods that could be used for military purposes. Japan also announced plans to phase out imports of Russian coal.
By Jacqueline Howard
Chernobyl's engineers tell tale of Russian occupation
Thousands of tanks and troops rumbled into the forested Chernobyl exclusion zone in the earliest hours of Russia's invasion of Ukraine in February, churning up highly contaminated soil from the site of the 1986 accident that was the world's worst nuclear disaster.
They held personnel still working at the plant at gunpoint during a marathon shift of more than a month, with employees sleeping on tabletops and eating just twice a day.
The plant's main security engineer, Valerii Semenov, told the Associated Press he worked 35 days straight, sleeping only three hours a night, rationing cigarettes and staying on even after the Russians allowed a shift change.
Workers kept the Russians from the most dangerous areas, but in what Mr Semenov called the worst situation he has seen in his 30 years at Chernobyl, the plant was without electricity, relying on diesel generators to support the critical work of circulating water for cooling the spent fuel rods.
Some soldiers even stole highly radioactive materials as souvenirs or possibly to sell.
"It was very dangerous to act in this way," said Maksym Shevchuck, the deputy head of the state agency managing the exclusion zone.
Mr Shevchuck believes hundreds or thousands of soldiers damaged their health, likely with little idea of the consequences, despite plant workers' warnings to their commanders.
The full extent of Russia's activities in the Chernobyl exclusion zone is still unknown, especially because the troops scattered mines that the Ukrainian military is still searching for.
Some have detonated, further disturbing the radioactive ground. The Russians also set several forest fires, which have been put out.
Ukrainian authorities can't monitor radiation levels across the zone because the Russian soldiers stole the main server for the system, severing the connection on March 2.
Mr Semenov recalled the Russians checking the remaining workers for what they called radicals.
"We said, 'Look at our documents, 90 per cent of us are originally from Russia,'" he said. "But we're patriots of our country," meaning Ukraine.
When the Russians hurriedly departed on March 31 as part of a withdrawal from the region that left behind scorched tanks and traumatised communities, they took more than 150 Ukrainian national guard members into Belarus. Mr Shevchuck fears they're now in Russia.
In their rush, the Russians gave nuclear plant managers a choice: Sign a document saying the soldiers had protected the site and there were no complaints, or be taken into Belarus. The managers signed.
By Jacqueline Howard
A 'new phase' of the war
Russia has hurled its military might against Ukrainian cities and towns this week and is pouring more troops into the war, seeking to slice the country in two in a potentially pivotal battle for control of the eastern industrial heartland of coal mines and factories.
The fighting on Tuesday unfolded along a boomerang-shaped front hundreds of kilometres long in the Donbas.
In Mariupol, Ukrainian troops said the Russian military dropped heavy bombs to flatten what was left of a sprawling steel plant and hit a hospital where hundreds were staying.
The eastern cities of Kharkiv and Kramatorsk came under attack.
Russia also said it struck areas around Zaporizhzhia and Dnipro west of the Donbas with missiles.
Russian Defence Ministry spokesman Major General Igor Konashenkov told the Associated Press Moscow's forces had bombarded numerous Ukrainian military sites, including troop concentrations and missile-warhead storage depots, in or near several cities or villages.
Both sides have described the assault that began this week as a new phase of the war.
By Jacqueline Howard
Russian diplomats depart Japan
A bus believed to be carrying Russian diplomats and their families was seen leaving the Russian embassy in Tokyo for the airport on Wednesday, according to the Associated Press.
A charter plane reportedly arranged by Russia was expected to fly from the Japanese capital to Moscow later in the day.
Japan announced earlier this month that it was expelling eight Russian diplomats and trade officials and would phase out imports of Russian coal and oil.
Japan has already faced reprisals from Moscow over the sanctions.
It suspended talks on a peace treaty with Tokyo that include negotiations over Russian-held islands which the Soviet Union seized from Japan at the end of World War II.
By Jacqueline Howard
When we report on battalion tactical groups, what are we actually talking about?
A Russian battalion tactical group, (BTG) is a self-contained unit which typically includes ground troops, air defence, armour, tactical vehicles, artillery and helicopters, as well as engineering and logistical support.
Most BTGs have between 700 to 800 personnel.
As Shiloh has said below, there are 78 Russian BTGs in the south and east of Ukraine. The US Department of Defense believes there are an additional 22 across the northern border of Ukraine being resupplied before reentering the country.
About a dozen of the BTGs inside Ukraine are trying to take Mariupol, a Pentagon official said in a press release update on US intelligence of the war.
By Jacqueline Howard
A 'cemetery' of shot-up cars in Irpin
Irpin, like nearby Bucha, was the scene of some of the fiercest fighting after Russia invaded Ukraine in February. Most residents fled, but those who stayed to fight alongside Ukrainian forces managed to defend the town.
Those who are left are doing what they can do clean up in the aftermath, like piling up all of the shot-up and burned-out cars that were left behind.
By Shiloh Payne
Russian adds two more combat units ahead of ‘battle of Donbas’
A senior US defence official, who spoke to Reuters on condition of anonymity, says two more Russian battalion tactical groups were sent to eastern Ukraine in the 24 hours before the latest offensive there.
Reuters reports that the total number of Russian battalion tactical groups in the country is now 78, all of them in the south and the east, up from 65 last week.
That would translate to about 55,000 to 62,000 troops, based on what the Pentagon said at the start of the war was the typical unit strength of 700 to 800 soldiers.
But Reuters says accurately determining Russia's fighting capacity at this stage is difficult.
By Shiloh Payne
Netflix's subscriber loss was partially caused by decision to withdraw from Russia
Netflix's quarterly earnings report released overnight revealed its customer base fell by 200,000, but the streaming service says the drop was partially because of its withdrawal of Russia to protest against the war in Ukraine.
The streaming service pulled out of Russia in March.
The company said the move resulted in the loss of about 700,000 subscribers.
By Shiloh Payne
This is what Ukrainian soldiers are seeing near the frontline in Mykolaiv
By Shiloh Payne
Ukrainian troops have so far held the line against a broad Russian offensive in Donbas
The general staff of Ukraine's armed forces has shared an operational update on Facebook, saying despite attacks in Kharkiv, a Russian offensive south of Izyum has failed.
Further south, Ukrainian troops have retaken the town of Marinka in the Donetsk region.
But Kyiv says Russia is transferring more troops from Belarus in order to redeploy them to the warzone.
By Shiloh Payne
A Ukrainian opera singer is dedicating her concerts in Japan to peace
Award-winning soprano Oksana Stepanyuk is using the power of song to unite her audience and address the war in Ukraine.
The Associated Press says the singer has been performing with the Japan Opera Foundation for two decades.
Ms Stepanyuk's concerts have free admission, but packed crowds are stuffing bills into the blue and yellow boxes at the door, filling them with donations for water, food and medicine in Ukraine.
“Music has no borders. I don’t have to say any words. Music will save this world,” she said.
“My voice I think is a gift from God. I feel on the stage that I have to give back to the audience everything that I have, my talent, my voice, my soul, my heart, and through my music they can feel what I am feeling."
By Shiloh Payne
Here's what it looks like in Kramatorsk where residents are evacuating as shelling continues
By Shiloh Payne
US treasury secretary blames Russia’s actions for world food insecurity
Higher food prices alone may push at least 10 million people into poverty, according to the US treasury secretary.
Janet Yellen said countries should avoid export bans that could further increase food prices and step up support for vulnerable populations.
"I want to be clear, Russia's actions are responsible for this," Ms Yellen said.
She said the state of world food security was "already dire", with price and supply shocks adding to inflation pressures.
Even before the war, more than 800 million people (10 per cent of the global population) were suffering from chronic food insecurity.
By Shiloh Payne
Russia gives Ukrainian fighters in Mariupol a fresh ultimatum
The Associated Press is reporting that Russia has once again called on Ukrainian troops at the Azovstal steel plant in Mariupol to surrender.
The Russian Defence Ministry said those who surrendered would be given medical treatment and allowed to live.
There hasn't been an immediate response from the Ukrainian troops, but they have repeatedly vowed not to give up.
Instead, the deputy commander of the Azov regiment, who is in Mariupol, said the Russian military dropped heavy bombs on the steel plant and hit an “improvised” hospital.
“We are pulling people out from under the rubble,” Sviatoslav Palamar said.
Serhiy Taruta, the former governor of the Donetsk region, also reported the bombing of the hospital, where he said 300 people, including wounded troops and civilians with children, were sheltered.
The Associated Press couldn't independently confirm the reports.
By Shiloh Payne
UN official says women and children escaping Ukraine must be protected from human trafficking and violence
More than 4 million refugees have fled Ukraine, but men aged between 18 and 60 can't leave and may be called on for military service.
Kelly Clements, the UN's deputy high commissioner for refugees, says this means many displaced girls and women travelling alone need protection.
"The risks of gender-based violence, trafficking and sexual exploitation and abuse are high," she said.
"Anecdotal information is already coming in about persons approaching the displaced with too-good-to-be-true promises of work, accommodation and transport."
By Shiloh Payne
Russia's Defence Minister accuses Western nations of doing all they can to drag out Russia’s invasion
Sergei Shoigu said Washington and its allies were supplying Ukraine with weapons so it could continue to resist Russia’s “special military operation”.
“The growing supplies of foreign weapons clearly signal their intention to provoke the Kyiv regime to keep fighting until the last Ukrainian,” he said.
Mr Shoigu said the Russian military had “consistently implemented the plan to fully liberate the Donetsk and Luhansk people’s republics”.
By Shiloh Payne
Phone communication between Chernobyl and the nuclear regulator has been restored
Reuters says Ukraine lost direct contact with the decommissioned Chernobyl power plant on March 10 after Russian forces seized the facility.
Rafael Mariano Grossi, the International Atomic Energy Agency's director general, said :"This was clearly not a sustainable situation, and it is very good news that the regulator can now contact the plant directly when it needs to."
The agency will head to Chernobyl to conduct a nuclear safety assessment, deliver equipment and repair the agency's own remote monitoring systems.
