Ukrainian authorities said Wednesday that Russian forces had bombarded the northern city of Chernihiv despite Moscow's earlier claims that it was "radically" scaling back military activity in the area.

"The enemy has demonstrated its 'decrease in activity' in the Chernihiv region with strikes on Nizhyn, including air strikes. Chernihiv was shelled all night," regional governor Vyacheslav Chaus wrote on social media. 

Speaking on local television, Chaus added later that "the situation is not changing," one day after Russia announced it would be changing tact.

"Chernihiv is under artillery and aerial bombardment. Last night, there were bombardments that destroyed the civil infrastructure," he added.

Delegations from Moscow and Kyiv held talks in Istanbul this week aimed at bringing to a close more than a month of fighting in Ukraine.

Russia's deputy defence minister Alexander Fomin said after that there had been progress on key Russian concerns and that Moscow's forces would "by several times reduce the military activity" around Kyiv and Chernihiv.

The mayor of war-scarred Chernihiv said late last week that the slow advance of Russian troops meant large-scale evacuations from the town were no longer possible.

This week he estimated the city's total fatalities since Russian launched its invasion at around 350 people.

Around 120,000 remain in the badly-damaged city of an estimated pre-invasion population of nearly around 280,000, he said.

"There is no water or electricity in the city. Communications are down and we can't repair them now," Chaus said Wednesday.

Ukrainian prosecutors earlier this month said 10 people were killed by Russian forces earlier while waiting in a line to collect bread in the northern city.