A Ukrainian official has said Russian shelling has killed five civilians over the past 24 hours and wounded 21 more in the eastern Donetsk province, where Russia has stepped up its offensive in recent days.

Donetsk governor Pavlo Kyrylenko said in a Telegram post on Wednesday morning that two people were killed in Avdiivka, one in Sloviansk, one in Krasnohorivka, and one in Kurakhove.

“Every crime will be punished,” he wrote.

On Tuesday, Mr Kyrylenko urged the province’s 350,000-plus residents to flee, saying that getting people out of Donetsk is necessary to save lives and enable the Ukrainian army better to defend towns from the Russian advance.

Donetsk is part of the Donbas, a mostly Russian-speaking industrial area where Ukraine’s most experienced soldiers are concentrated.

Pro-Russian separatists have fought Ukrainian forces and controlled much of the Donbas for eight years.

Before the invasion this year, Russian President Vladimir Putin recognised the independence of the two self-proclaimed separatist republics in the region.

He also sought to portray the tactics of Ukrainian forces and the government as akin to Nazi Germany’s, claims for which no evidence has emerged.

Russian forces also hit Kharkiv, Ukraine’s second largest city further to the north, with missile strikes overnight, the governor of Kharkiv region Oleh Syniehubov said on Telegram on Wednesday.

Three districts of the city were targeted, Mr Syniehubov said, and a university building was destroyed, as well as one administrative building.

Three people, including a toddler, sustained injuries, according to the governor.