Ukraine has driven Russian troops away from the second-largest city of Kharkiv in the fastest advance since Kremlin forces pulled away from Kyiv and the northeast over a month ago although Russia is still bombarding villages north of Kharkiv.
The city, which had been under fierce bombardment, has been quiet for at least two weeks and Reuters journalists have confirmed Ukraine controls territory stretching to the Siverskyi Donets River, about 40km to the east.
About 10km north of the city, firefighters doused smouldering wreckage in Dergachi after what local officials said was an overnight Russian missile attack on the House of Culture, used to distribute aid.
Volunteers inside were trying to salvage packages of baby diapers and formula.
"I can't call it anything but a terrorist act," the mayor, Vyacheslav Zadorenko, told Reuters.
"They wanted to hit the base where we store provisions and create a humanitarian catastrophe."
Another missile had slammed into the building on Thursday and Russian shelling had wounded a staff member at a clinic and killed a young couple in their home, he said.
Russia, which denies targeting civilians, said its forces had shot down a Ukrainian Su-27 aircraft in the Kharkiv region and disabled the Kremenchuk oil refinery in central Ukraine.
It was not immediately possible to verify the reports.
Southeast of Kharkiv, the United Kingdom said Ukraine had stopped Russian forces crossing the Siverskyi Donets river west of Severodonetsk.
Footage released by Ukrainian Airborne Forces Command appeared to show several burnt out military vehicles near segments of a partially submerged bridge and many other damaged or abandoned vehicles, including tanks, nearby.
Reuters could not immediately verify the report or when or where the clash took place.
The UK defence ministry said Russia was investing significant military effort near Severodonetsk and Izium, and trying to break through towards Sloviansk and Kramatorsk to complete their takeover of Ukraine's industrial Donbas region.
Russian-backed separatists said they had taken the Zarya chemical plant in Rubizne near Severodonetsk.
The Kremlin calls its February 24 invasion of Ukraine a "special military operation" to demilitarise a neighbour threatening its security.
Ukraine says it poses no threat to Russia and that the deaths of thousands of civilians and destruction of cities and towns show that Russia is waging a war of aggression.
US Defense Secretary Lloyd Austin spoke by telephone to his Russian counterpart Sergei Shoigu on Friday and called for an immediate ceasefire in Ukraine.
It was the first time since the invasion that the two men had spoken.
Austin stressed the importance of maintaining lines of communication, the Pentagon spokesman said.
In the southern port of Mariupol, Russian forces intensified their bombardment of the Azovstal steelworks, the last bastion of Ukrainian defenders in a city almost completely controlled by Russia after a siege of more than two months.
Deputy Prime Minister Iryna Vereshchuk told 1+1 television negotiations were underway to allow wounded troops to leave.
In Germany, foreign ministers from the G7 met to discuss a planned European Union embargo on Russian oil as well as fears the conflict could spill over into Moldova.
Ukrainian Foreign Minister Dmytro Kuleba told the meeting he hoped EU holdout Hungary would agree to the oil embargo and asked the G7 to hand over Russian assets to help Ukraine rebuild.
"We are talking about hundreds of billions of dollars. Russia must pay," he told reporters.
A day after Russia's northeastern neighbour Finland committed to applying to join NATO, Swedish Foreign Minister Ann Linde said membership for her country would have a stabilising effect and benefit countries around the Baltic sea.
Joining the 30-member military alliance would end the neutrality the two states maintained throughout the Cold War and further the expansion of NATO that Russia has said its invasion of Ukraine aimed to prevent.
NATO member Turkey said it did not support the idea.
The US said it was working to clarify Turkey's position.
Russia has called Finland's announcement hostile and threatened retaliation but said a newspaper report the Kremlin might cut gas supplies to Finland was mostly likely a "hoax".
