German Chancellor, Angela Merkel, has demanded an explanation from Russia’s President Vladimir Putin, amid reports that Russian troops have launched an incursion into South-East Ukraine.
Ukraine said Russian forces had crossed the border and were supporting rebel attacks. The rebels have opened a new front near the port of Mariupol.
Ukraine’s security and defence council said on Thursday the border town of Novoazovsk and other parts of Ukraine’s South-East had fallen under the control of Russian forces who together with rebels were staging a counter-offensive.
“A counter-offensive by Russian troops and separatist units is continuing in South-East Ukraine,” the council said in a post on Twitter.
It said Ukrainian government forces had withdrawn from Novoazovsk “to save their lives” and were now reinforcing troops in the port city of Mariupol.
It added that Russian forces and separatists were combining to launch a counter-offensive on Ilovaysk and Shakhtarsk, east of the big city of Donetsk.
The U.S. also said it suspected a Russian-directed counter-offensive was ongoing.
Russia has repeatedly denied arming or covertly supporting the rebels.
Reports say the suspicion is that Moscow is opening a new front to divert Ukrainian forces from the besieged cities of Donetsk and Luhansk, where they have made significant advances against pro-Russian separatists.
However, Denis Pushilin, a rebel leader in Donetsk, told a news conference that Russia was not involved in the current offensive.