Ukrainian sources report that over 2,800 civilians have been evacuated from some of the most fiercely contested cities in eastern Ukraine.
Some 2,500 refugees arrived in the southern city of Zaporizhzhya on Friday, including 363 from the devastated port city of Mariupol, Ukrainian Deputy Prime Minister Iryna Vereshchuk announced on Telegram.
Earlier, the Kharkiv Oblast prosecutor's office reported that seven civilians had been killed by Russian soldiers while attempting to use a safe corridor to escape the village of Borova by bus. A further 27 people were reportedly injured in the attack.
The Ukrainian government also alleged that Russia had employed Tu-22M3 supersonic bombers in the conflict, using them to bomb the largely destroyed port city of Mariupol, where fighting continued, despite Russian claims to be in total control, according to Ukrainian Defence Ministry spokesperson Oleksandr Motuzyanyk.
No aid convoys had been allowed into the city of Mariupol since it was surrounded by Russian forces two weeks ago, World Food Programme (WFP) chief David Beasley said on Friday after a visit to Ukraine. Some 100,000 people are believed to still be in the city, but the last supplies of food and water would soon be exhausted, he added.
Elsewhere in Ukraine, Russian forces continued to bombard the towns of Popasna and Rubizhne in Ukraine's eastern Luhansk region, the Ukrainian military said.
Kyiv, which is strengthening its troop numbers in the area, expects a larger-scale Russian offensive in eastern Ukraine in the coming days after the Kremlin switched its focus from the capital and areas in the north.
Russian troops previously deployed near the northern city of Chernihiv are now stationed around Severodonetsk in the Luhansk region, the Ukrainian military report said.
If confirmed, this would be the first unit to have been withdrawn and redeployed to eastern Ukraine from north-eastern Ukraine, according to the U.S.-based Institute for the Study of War (ISW).
"These units likely remain degraded, and Russian forces will face challenges integrating units from several military districts into a cohesive fighting force," ISW said in an assessment.
Russian-backed separatists have already been fighting in Donetsk and Luhansk since 2014, but Moscow is reinforcing them now. Ukraine said it had destroyed several Russian tanks and an artillery system in the area over the past 24 hours.
According to United Nations figures, more than 4.7 million Ukrainians have left Ukraine since the war began in late February, with another 7 million people being internally displaced by the conflict.
Despite its pivot to the east, Russia is not ignoring Kyiv entirely. The Russian Defence Ministry said it had attacked a missile factory just southwest of Kyiv on Friday, though there was no confirmation of the claim from the Ukrainian side.
Moscow has repeated threats to renew attacks on Kyiv if Ukrainian troops carry out "acts of sabotage" on Russian territory.
Russia has accused a Ukrainian combat helicopter of attacking targets in western Russia, something the SBU, Ukraine's secret service, denied in a Facebook post on Friday.
Russia is also attempting to create a land bridge connecting the Donbass region with the Crimean peninsula, which it annexed illegally from Ukraine in 2014.