Thirty-three people died Thursday when Russian forces hit residential areas, including schools and a high-rise apartment building, in the northern Ukrainian city of Chernihiv, officials said.

Ukraine's emergencies service said 18 people were also injured in the attack, updating an earlier toll.

The town of Chernihiv lies 120 kilometres (75 miles) northeast of Kyiv, which the Russian forces have been trying to invade from the north.

Chernihiv's deputy mayor Regina Gusak told AFP that the city was hit by a Russian "bombing attack".

Ukraine's emergencies service released images showing plumes of smoke coming out of heavily damaged apartments, with debris scattered across a yard and rescuers carrying bodies on stretchers.

"Russian aircraft also attacked two schools in the Staraya Podusivka area (of Chernihiv) and private homes. Rescuers are working in the area," the governor of the Chernihiv region, Vyacheslav Chaus, said on Telegram. 

Since it invaded Ukraine a week ago, Russia has said that it does not target civilian areas, despite widespread evidence to the contrary.

Ukraine says at least 350 civilians have been killed since Russian President Vladimir Putin launched his attack.

The strikes came as Ukraine and Russia officials gathered for talks on a ceasefire on the Belarus-Poland border Thursday. 

Putin on Thursday vowed to carry on with his advance in Ukraine in a phone call with French President Emmanuel Macron.

The Russian leader has showed no signs of backing down even as a barrage of Western sanctions is set to destroy Moscow's economy.