Saturday's bombardments hit four towns around and to the southeast of Kharkiv, Oleg Synegubov posted on Telegram, adding that one of those killed was a child.

"In the course of the day, the occupiers bombarded the civil infrastructure at Balakliya, Pesochin, Zolochiv and Dergachi," he added.

"At the current time we know of 10 people killed, including a child, and 11 wounded."

Kharkiv, Ukraine's second-largest city, had a population of around 1.5 million before the war.

Located about 40 kilometres (25 miles) from the Russian border, it has been the site of fierce fighting since the start of the invasion on February 24, but has not been captured by Moscow's forces.

In recent days, Russian troops have pulled back from Kharkiv region towards the east and south of Ukraine.