DERGACHI, UKRAINE (REUTERS) - Ukrainian forces destroyed parts of a Russian armoured column as it tried to cross a river in the Donbas region, video from Ukraine's military showed on Friday (May 13), as the Ukrainian defence minister predicted many weeks of grinding fighting ahead.
Ukrainian forces have driven Russia from the second-largest Ukrainian city of Kharkiv in their fastest advance since Kremlin troops pulled away from Kyiv and the north-east over a month ago to focus their offensive on the Donbas region bordering Russia.
The city, which had been under fierce bombardment, has been quiet for at least two weeks and Reuters journalists have confirmed Ukraine now controls territory stretching to the Siverskyi Donets River, around 40km to the east.
However, Moscow is still bombarding villages north of Kharkiv.
Some 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.
South-east of Kharkiv, Britain 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 Kremlin calls its Feb 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 Russia is waging a war of aggression.
"We are entering a new, long phase of the war," Ukrainian Defence Minister Oleksii Reznikov said in a Facebook post, predicting "extremely tough weeks" ahead during which he said Ukraine would largely be alone against an "enraged aggressor".
The British 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.
In their first conversation since the invasion, US Defence Secretary Lloyd Austin spoke by telephone on Friday with Russian Defence Minister Sergei Shoigu, calling for an immediate ceasefire and stressing the importance of maintaining lines of communication, the Pentagon spokesman said.
Kyiv says children deported
Ukraine accused Russia of forcibly deporting more than 210,000 children since its invasion, saying they were among 1.2 million Ukrainians transferred against their will. The Kremlin says people have come to Russia to escape fighting.
In Kyiv, a court began hearing the first case of what Ukraine says are more than 10,000 possible war crimes. A Russian soldier is accused of murdering a civilian. Moscow has accused Kyiv of staging such crimes.
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.
Some of the civilians evacuated recently from tunnels under the plant where they sheltered described terrifying conditions.
"Every second was hellish," 51-year-old nurse Valentyna Demyanchuk told Reuters.
In an online post, Ukrainian Deputy Prime Minister Iryna Vereshchuk said "very difficult" negotiations were under way with Russia on getting Ukrainian defenders out of the besieged plant but gave no details.
Russian ship set alight
Renewed fighting in recent days around Snake Island, an outpost that Ukrainian military intelligence said allows control of civilian shipping, could help Ukraine resume grain exports vital to world supplies, some of which are now being shipped by rail.
"There are 25 million tonnes of grain currently blocked in the Ukrainian port of Odesa, which means food for millions of people in the world that is urgently needed," German Foreign Minister Annalena Baerbock said.
Ukraine said it had damaged a Russian navy logistics ship near Snake Island. Russia's defence ministry did not respond to a request for comment.
Satellite imagery from Maxar, a private US-based company, showed the aftermath of what it called probable missile attacks on a Russian landing craft near the island, which became famous for its Ukrainian defenders' expletive-filled defiance early in the war.
Meeting in Germany, foreign ministers from the G-7 group of rich nations backed giving more aid and weapons to Ukraine.
The European Union's foreign policy chief Josep Borrell announced a further 500 million euros worth of military support that should be approved next week by EU members, and expressed confidence that the bloc will agree an embargo on Russian oil.
Ukrainian Foreign Minister Dmytro Kuleba told the meeting he hoped EU holdout Hungary would agree to the oil embargo and asked the G-7 to hand over Russian assets to help Ukraine rebuild.
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-nation Western military alliance would end the neutrality the two states maintained throughout the Cold War and further the expansion of Nato that Putin said his invasion of Ukraine aimed to prevent.
Nato member Turkey said it did not support the idea. The United States said it was working to clarify Turkey's position.
Moscow 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".