Ukrainians boarded buses to flee the surrounded eastern city of Sumy on Tuesday, the first evacuation from a Ukrainian city through a humanitarian corridor agreed with Russia after several failed attempts in recent days.
Sumy governor Dmitro Zhivitskiy said in a video statement that the first buses had already departed Sumy for the city of Poltava, further west. He said priority would be given to the disabled, pregnant women and children in orphanages.
A short video clip released by presidential advisor Kyrolo Tymoshenko showed a red bus with some civilians on board.
"It has been agreed that the first convoy will start at 10 am (0800 GMT) from the city of Sumy. The convoy will be followed by the local population in personal vehicles," Deputy Prime Minister Iryna Vereshchuk said in a televised statement.
Residents were also leaving the town of Irpin, a frontline Kyiv suburb where Reuters journalists had filmed families fleeing for their lives under fierce bombardment on Sunday. Residents ran with their young children in strollers or cradling babies in arms, while others carried pets and plastic bags of belongings.
"The city is almost ruined, and the district where I'm living, it's like there are no houses which were not bombed," said one young mother, holding a baby beneath a blanket, while her daughter stood by her side.
"Yesterday was the hardest bombing, and the lights and sound are so scary, and the whole building is shaking."
Russia's Interfax news agency said Moscow was opening corridors on Tuesday to allow people to leave five Ukrainian cities: Cherhihiv, Kharkiv, Mariupol and the capital Kyiv, as well as Sumy. There was no immediate comment from the Ukrainian side on evacuations from cities apart from Sumy.
Russian and Ukrainian officials had agreed on similar corridors to evacuate residents from the besieged port of Mariupol in the south on Saturday and Sunday, but both those attempts failed, with each side accusing the other of continuing to fire.
Moscow describes its actions in Ukraine as a "special operation" to disarm its neighbour and arrest leaders it calls "neo-Nazis". Ukraine and its Western allies call this a baseless pretext for an invasion to conquer a country of 44 million people.
Russia's attack has sent 1.7 million refugees fleeing to other countries. Western sanctions have cut off Russia from international trade to a degree never before imposed on such a big economy.
Russia is the world's leading exporter of oil and gas, and both Russia and Ukraine are major suppliers of grain and metals, creating concern that the conflict could cause massive supply disruptions and derail the global recovery from the coronavirus pandemic.
Ukraine claimed the pace of Russia's advances had slowed on Tuesday. Its defence ministry also claimed that Russian Major General Vitaly Gerasimov, first deputy commander of Russia's 41st army, had been killed on Monday, the second Russian major general killed since the attack began.
Russia's defence ministry could not be immediately reached for comment and Reuters could not verify the reports.
Negotiations have so far focused mainly on allowing safe passage for civilians to escape bombardment from cities that are surrounded by Russian forces. Sumy in the east and Mariupol in the south have been among the hardest hit by Russia's assault.
Russia had said it would require those fleeing from Kyiv or Kharkiv to go to Russia itself or its ally Belarus, conditions rejected by Ukraine. Those leaving Sumy or Mariupol would be permitted to go to other parts of Ukraine.
To the south, Russia has made more progress along the Black and Azov Sea coasts.
Fears of an energy war between Russia and the West have grown this week, after the United States pushed its allies to ban Russian oil imports. Sanctions so far have made an exception for Russian energy exports.
US President Joe Biden held a video conference call with the leaders of France, Germany and Britain on Monday. The United States is not a major buyer of Russian energy, but Russia supplies 40% of Europe's gas, and European allies have indicated so far that they are not in a position to halt Russian energy supplies.
Russian Deputy Prime Minister Alexander Novak said on Monday Russia could halt gas deliveries to Germany in retaliation for Berlin suspending a new pipeline. Oil prices could more than double to $300 a barrel if the United States and its allies banned imports of Russian oil, he said.
A senior U.S. defence official said Putin had now deployed nearly 100% of the more than 150,000 troops that he had pre-staged outside Ukraine before the invasion.