Russia has fired two missiles into the Ukrainian capital Kyiv during a visit by the UN secretary-general, with one hitting the lower floor of a residential building and injuring at least three people, the city's mayor says.
Kyiv has enjoyed relative calm since Russian invasion forces failed to capture it in the face of stiff Ukrainian resistance and withdrew several weeks ago, but remains vulnerable to longer-range Russian heavy weaponry.
The blasts shook Kyiv's central Shevchenko district and struck the lower floors of a 25-storey residential building, leaving at least 10 people injured, Ukrainian officials said.
The cause of the explosions has not been independently verified.
Defence Minister Oleksii Reznikov and Foreign Minister Dmytro Kuleba both said the blasts were caused by Russian missiles.
Reuters witnesses had earlier reported the sound of two blasts.
The bombardment came barely an hour after Ukrainian President Volodymyr Zelenskyy held a news conference with UN Secretary-General António Guterres, who said Ukraine has become "an epicentre of unbearable heartache and pain."
There was no immediate Russian comment on the blasts.
A spokesperson said Mr Guterres and his team were safe.
Mr Guterres and Mr Zelenskyy had completed talks focusing on efforts to evacuate civilians from the Russian-besieged southern port of Mariupol.
Mr Guterres told Portuguese broadcaster RTP that news of the blasts came as a shock.
Mr Zelenskyy said the strikes showed it was "too early to relax" when it comes to Russia's invasion of Ukraine.
"We can't think that the war is reaching its end. We must still fight and push away the occupiers," he said.
Russia warns West 'not to test patience'
A warning has been issued by Russia to the West that there would be a tough military response to any further attack on Russian territory, accusing the United States and its key allies of undermining European security by openly inciting Ukraine to launch assaults on its soil.
Russia's February 24 invasion of Ukraine has seen thousands of people die, displaced millions more and raised fears of the most serious confrontation between Russia and the United States since the 1962 Cuban Missile Crisis.
In recent days, Russia reported what it said was a series of attacks by Ukrainian forces on Russian regions that border Ukraine, and has warned that such attacks risk a significant escalation of military action.
Ukraine has not directly accepted responsibility but says the incidents are payback, while Russia has taken umbrage at statements from NATO-member Britain that it is legitimate for Ukraine to target Russian logistics.
"In the West, they are openly calling on Kyiv to attack Russia, including with the use of weapons received from NATO countries," Russian Foreign Ministry spokeswoman Maria Zakharova told reporters in Moscow.
Ms Zakharova warned that "further inciting of Ukraine to strike Russian territory will definitely lead to a tough response from Russia".
The Kremlin said Western — and, in particular, British — attempts to supply heavy weapons to Ukraine threatened the security of Europe.
"In itself, the tendency to pump weapons, including heavy weapons, to Ukraine and other countries are actions that threaten the security of the continent and provoke instability," Kremlin spokesman Dmitry Peskov told reporters.
Sergei Naryshkin — the chief of Russia's Foreign Intelligence Service (SVR) — accused the United States and Poland of plotting to gain a sphere of influence in Ukraine, the strongest signal from Moscow that the war could end with a forced partition of Ukraine between the West and Russia.
Russia — whose invasion of Ukraine has killed many thousands of people and displaced millions — has consistently portrayed NATO and the West as aggressors who have forced it into defending its own security.
On Wednesday, Russian President Vladimir Putin issued a stark warning after the initial attacks.
"If someone intends to intervene in the ongoing events from the outside, and create strategic threats for Russia that are unacceptable to us, they should know that our retaliatory strikes will be lightning-fast," Mr Putin said.
The United States has ruled out sending its own or NATO forces into Ukraine but Washington and its European allies have supplied weapons to Kyiv, such as drones, Howitzer heavy artillery, anti-aircraft Stinger and anti-tank Javelin missiles.
Total US security assistance since the invasion amounts to about $US3.7 billion ($5.2 billion), a US official said.
Hundreds of bodies recovered in Kyiv
The bodies of 1,150 civilians have been recovered in Ukraine's Kyiv region since Russia's invasion and 50 to 70 per cent of them have bullet wounds from small arms, Kyiv police said on Thursday.
Kyiv regional police chief Andriy Nebytov said in a video posted on Twitter that most of the bodies had been found in the town of Bucha, where hundreds of corpses have been discovered since Russian forces withdrew.
Ukraine says the civilians found dead in Bucha were killed by Russian forces during their occupation of the area.
Reuters has not been able to verify the number of people found dead in Bucha nor the circumstances of their deaths.
Russia denies targeting civilians and has called allegations that Russian forces executed civilians in Bucha while they occupied the town a "monstrous forgery" aimed at denigrating the Russian army.
"To date, we have found, examined and handed over to forensic institutions, 1,150 bodies of dead civilians," police chief Nebytov said in the video, in which he stood in the rubble of buildings destroyed during heavy fighting in the Kyiv region.
The video was posted on the day that United Nations Secretary-General António Guterres held talks in Kyiv with Ukrainian President Volodymyr Zelenskyy.
Ukrainian television showed Mr Guterres visiting the town of Borodyanka, where Mr Zelenskyy said the situation was "significantly more dreadful" than in nearby Bucha.
UN Security Council 'failed' to prevent war
During a joint press conference with Mr Zelenskyy, Mr Guterres criticised the 15-member UN Security Council for its inability to thwart Russia's invasion of Ukraine.
"Let me be very clear, the Security Council failed to do everything in its power to prevent and end this war.
"And this is a source of great disappointment, frustration and anger," he said.
The UN chief also told reporters a green corridor was urgently needed for civilians trapped in the besieged port city of Mariupol.
"Mariupol is a crisis within a crisis. Thousands of civilians need life-saving assistance. Many are elderly, in need of medical care or have limited mobility," Mr Guterres said.
Referring to the possibility of a United Nations and ICRC-coordinated humanitarian corridor for the hundreds of civilians believed to still be in the Azovstal steel plant, Mr Guterres said: "As we speak, there are intense discussions to move forward on this proposal to make it a reality.
Russia blocks evacuation of Mariupol's wounded fighters
Russia is preventing wounded Ukrainian fighters from being evacuated from a vast steelworks in the southern city of Mariupol because it wants to capture them, the local governor said on Thursday.
Pavlo Kyrylenko — the governor of the eastern region of Donetsk — said Russia was also blocking efforts to arrange humanitarian corridors elsewhere in Donetsk but that Russian forces were being held back across his region.
Hundreds of fighters and some civilians are holed up in the Azovstal steelworks, their last redoubt in Mariupol.
Russian forces have been pummelling the factory after laying siege to Mariupol for weeks, but President Vladimir Putin has said the plant need not be stormed.
"They [want to] use the opportunity to capture the defenders of Mariupol, one of the main [elements] of whom are the … Azov regiment," Mr Kyrylenko told a briefing, referring to a group of fighters that Moscow has vilified.
"Therefore, the Russian side is not agreeing to any evacuation measures regarding wounded [Ukrainian] troops."
Kremlin spokesman Dmitry Peskov said Mr Putin had been quite clear that while civilians could leave the plant, the defenders had to lay down their arms, Russia's TASS news agency said.
"What could be the topic of negotiations in this case?" the agency quoted him as saying
Mariupol's city council said about 100,000 city residents were "in mortal danger" because of Russian shelling and unsanitary conditions.
It said the shortage of drinking water and food was "catastrophic".
Russia has mounted a push to seize Donetsk and another eastern province in the second stage of its invasion.
Mr Kyrylenko said that, despite the lack of agreements on humanitarian corridors, only 370,000 residents remained in Ukrainian-controlled parts of the Donetsk region, compared to 1.67 million before Russia's invasion.
More than 270,000 have fled the Donetsk region on trains and nearly 80,000 have gone by road, he said.
ABC/wires
