KIEV/BRUSSELS - Ukraine said Russian tanks had flattened a small border town and pro-Russian rebels had made fresh gains in its east, as EU leaders signalled on Saturday they would threaten more sanctions against Moscow over the crisis.
Ukrainian President Petro Poroshenko, attending an EU summit in Brussels, said he was hoping for a political solution, but warned that his country was on the brink of full-scale war.
Russia has repeatedly dismissed accusations from Kiev and Western powers that it has sent soldiers into its neighbour, or supported pro-Russian rebels fighting a five-month-old separatist war in Ukraine's east.
But Ukraine military spokesman Andriy Lysenko told journalists in Kiev that Russian tanks had entered the small Ukrainian town of Novosvitlivka on the border with Russia and fired on every house.
"We have information that virtually every house has been destroyed," Lysenko added, without giving details on when the reported attack took place. Ukraine's daily military briefings typically cover the previous 24 hours.
Lysenko said the rebels had made new gains just east of the border city of Luhansk, one of the rebels' main strongholds, after opening up a new front in another area last week.
"Direct military aggression by the Russian Federation in the east of Ukraine is continuing. The Russians are continuing to send military equipment and 'mercenaries'," Ukraine's defence and security council said in a separate Twitter post.
Kiev and Western countries say recent rebel gains were the result of the arrival of armoured columns of Russian troops, sent by Russian President Vladimir Putin to prop up a separatist rebellion that would otherwise have been near collapse.
There was no immediate fresh comment from Russia on Saturday. Putin on Friday compared Kiev's drive to regain control of its rebellious eastern cities to the Nazi invasion of the Soviet Union in World War Two.