Russia missiles have struck "critical infrastructure", most likely a fuel depot, near Ukraine's southern port city of Odesa but there were no casualties, officials in the city said.
Odesa, on the Black Sea coast, is a key port and the main base for Ukraine's navy.
It has been a focus for Russian forces, and if taken would allow Moscow to build a land corridor to Transdniestria, a Russian-speaking breakaway province of Moldova that hosts Russian troops.
Russia's defence ministry said missile strikes by its military destroyed an oil refinery and three fuel storage facilities near Odesa on Sunday, adding the facilities were used by Ukraine to supply its troops near the city of Mykolaiv.
Vladyslav Nazarov, an officer of Ukraine's South Operational Command, said on Telegram: "Russia began with a missile strike. The Odesa region was among the priority targets. The enemy continued its vile practice of strikes against critical infrastructure."
Vika, a local resident who declined to give her surname, said it was "not a good morning for Odesa".
"We woke up to powerful explosions near our home. There was smoke, the children were in a panic, the windows were blown in… it was terrifying," she told Reuters.
"'Russian peace', we are completely not happy that it has come and we ask you to leave."
Turkey offers to help evacuate Mairupol
Turkey has offered to help evacuate civilians from the besieged Ukrainian port city of Mariupol by ship.
The Turkish defence minister said Saturday that "we can provide ship support for the evacuation of civilians and injured Turkish and other countries' citizens in Mariupol from the sea."
State-run Anadolu Agency reported that Hulusi Akar said Turkey was coordinating possible evacuations with the authorities of the Russian Federation and Ukraine.
Mariupol, on the Sea of Azov, has seen some of the worst suffering of the war.
Encircled since the early days of Russia's five-week old invasion, Mariupol has been Moscow's main target in Ukraine's south-eastern region of Donbas.
Tens of thousands are trapped with scant access to food and water.
The International Committee for the Red Cross is attempting to remove some of the 100,000 people are believed to remain in the city.
Turkish Foreign Minister Mevlut Cavusoglu said Friday that some 30 Turkish nationals were still in the city.
Turkey, which has good relations with both Russia and Ukraine, has sought to mediate the conflict, with Turkey hosting peace talks last month.
Plans for fresh Mariupol evacuation efforts
A Red Cross convoy will try again to evacuate civilians from Mariupol on Sunday with buses attempting to come close to the besieged city, Ukrainian Deputy Prime Minister Iryna Vereshchuk said.
"Seven buses will try to get closer to Mariupol, accompanied by the International Committee of the Red Cross," Ms Vereshchuk said in an online video posting.
There will be 17 buses prepared to evacuate people from Mariupol and Berdyansk, she said.
The International Committee of the Red Cross (ICRC) sent a team on Friday to lead a convoy of about 54 Ukrainian buses and other private vehicles out of the city, but they turned back, saying conditions made it impossible to proceed.
A previous Red Cross evacuation attempt in early March failed.
An advisor to the Ukrainian president said he was hopeful about the Mariupol evacuations.
Russia and Ukraine have agreed to humanitarian corridors during the war to facilitate the evacuation of civilians from cities, but have often traded blame when the corridors have not been successful.
After failing to take a major Ukrainian city since it launched the invasion, Russia says it has shifted its focus to the south-east, where it has backed separatists since 2014.
In an early morning video address, Mr Zelenskyy said Russian troops had moved toward Donbas and the heavily bombarded north-eastern city of Kharkiv.
Russia said on Sunday that peace talks had not progressed enough for a leaders' meeting and that Moscow's position on the status of Crimea and Donbas remained unchanged.
Pope indirectly criticises Putin
Pope Francis came the closest yet to implicitly criticising President Vladimir Putin over Russia's invasion of Ukraine, saying a "potentate" — an autocratic ruler — was fomenting conflicts for nationalist interests.
In Malta for a two-day visit following his apology to Indigenous people who suffered abuse in Canada's residential schools, the Pope spoke of "dark shadows of war" spreading across Europe.
"We had thought that invasions of other countries, savage street fighting and atomic threats were grim memories of a distant past," he said in an address to Maltese officials.
"However, the icy winds of war, which bring only death, destruction and hatred in their wake, have swept down powerfully upon the lives of many people and affected us all.
Pope Francis has already strongly condemned what he has called an "unjustified aggression" and denounced "atrocities" in the war.
But he has only referred to Russia directly in prayers, such as during a special global event for peace on March 25.
"Now, in the night of the war that is fallen upon humanity, let us not allow the dream of peace to fade!" he said on Saturday.
Earlier, Francis said he was considering a trip to the Ukrainian capital, Kyiv.
Asked by a reporter on the plane taking him from Rome to Malta if he was considering an invitation made by Ukrainian political and religious authorities, the Pope answered: "Yes, it is on the table", without giving details.
Francis has been invited by Ukrainian President Volodymyr Zelenskyy, Kyiv Mayor Vitaliy Klitschko, Major Archbishop Sviatoslav Shevchuk of Ukraine's Byzantine-rite Catholic Church and Ukraine's ambassador to the Vatican, Andriy Yurash.
He has spoken on the phone with Mr Zelenskyy and Mr Shevchuk.
Reports of gunfire used to disperse pro-Ukraine rally
Local authorities in the occupied Ukrainian town of Enerhodar said Russian forces had violently dispersed a pro-Ukrainian rally on Saturday and detained some participants.
Residents had gathered in the centre of the town in the south of the country to talk and sing the Ukrainian national anthem when Russian soldiers arrived and bundled some into detention vans, the local administration said in an online post.
"The occupiers are dispersing the protesters with explosions," it said in a separate post on Telegram, sharing a video of what appeared to be multiple stun grenades landing in a square and letting off bangs and clouds of white smoke next to the town's main cultural centre.
It also accused Russian forces of shelling another part of the town on Saturday and said as a result four people had been wounded and were being treated in hospital.
Reuters could not immediately verify the video or the local administration's reports.
Enerhodar lies on the Dnieper River in southern Ukraine and is home to workers of the nearby Zaporizhzhia nuclear power plant, Europe's largest, which has also been occupied by Russian troops.
Calls for global arrest warrant for Putin
The former chief prosecutor of the International Criminal Court (ICC) has called for an international arrest warrant to be issued for the Mr Putin.
"Putin is a war criminal," Carla Del Ponte told the Swiss newspaper Le Temps in an interview published on Saturday.
The Swiss lawyer who oversaw ICC war crimes investigations in Rwanda, Syria and the former Yugoslavia said there were clear war crimes being committed in Ukraine.
She said she was particularly shocked by the use of mass graves in Russia's war on Ukraine, which recalls the worst of the wars in the former Yugoslavia.
"I hoped never to see mass graves again," she told the Swiss newspaper Blick.
She said the investigation in Ukraine would be easier than that in Yugoslavia because the country itself had requested an international probe.
If the ICC finds proof of war crimes, she said, "you must go up the chain of command until you reach those who took the decisions."
Reuters/AP
