As Russian troops continued pressing their offensive Friday, intense fighting also raged in the country's east.

Russian troops entered the city of Sumy near the border with Russia that sits on a highway leading to Kyiv from the east. The regional governor, Dmytro Zhivitsky, said Ukrainian forces fought Russian troops in the city overnight, but other Russian convoys kept rolling west toward the Ukrainian capital.

“Military vehicles from Sumy are moving toward Kyiv,” Zhivitsky said. “Much equipment has passed through and is heading directly to the west.”

Zhivitsky added that another northeastern city, Konotop, was also sieged. He urged residents of the region to fight the Russian forces.

The Hague: The prosecutor of the International Criminal Court says he is “closely following recent developments in and around Ukraine with increasing concern.”

Karim Khan issued a statement Friday on Twitter while on a visit to Bangladesh, where he is investigating crimes against Myanmar's Rohingya minority.

Khan said he alerted “all sides conducting hostilities on the territory of Ukraine” that Ukraine has accepted the court's jurisdiction.

That means “my office may exercise its jurisdiction over and investigate any act of genocide, crime against humanity or war crime committed within the territory of Ukraine since 20 February 2014 onwards," Khan added.

He said that “any person who commits such crimes, including by ordering, inciting or contributing in another manner to the commission of these crimes may be liable to prosecution before the Court.”

Khan added that because neither Russia nor Ukraine are member states of the court, his office does not have jurisdiction over the crime of aggression in the conflict.

The International Criminal Court is the world's permanent war crimes court. It was set up in 2002 to prosecute atrocities in countries where local authorities are unable or unwilling to conduct trials.