Russia appears to have increased efforts somewhat in the northeast, around Ukraine's second-largest city of Kharkiv, where forces were previously pushed back by a Ukrainian counter-offensive.

Russian forces are said to have also tried to break through the Ukrainian line in the direction of, among other things, Bazaliivka, five miles east of Kharkiv, without success, the Ukrainian armed forces said on Wednesday evening.

Limited successes

The US-based think tank ISW writes in its daily update that Russian forces made several unsuccessful attacks near the border between the Kharkiv and Donetsk regions in "tactically challenging forest areas", while the Russian attacks in the Donetsk region itself also continued, with little or no success.

In the city of Kharkiv, Russian rockets hit homes on Wednesday, killing at least seven civilians and wounding 17, the city's mayor Igor Terekhov said on Telegram.

"What happened on Wednesday night proved once again that this is not a war between two armies.

They fight for our death as a people.

That's why they attack houses.

And we fight for our lives.

And no matter how much Ukraine and Kharkiv are bombed, we will not only survive, but also win," he writes.

Several cities attacked

There is concern about a Russian build-up in the north, along the border with Belarus, Ukraine's Commander-in-Chief Valery Zaluzhny says in a statement.

According to him, robotic systems have been set up there, while the Russian bombardment along the entire front is intense.

“The enemy carries out about 700-800 artillery attacks on our positions daily, using 40,000 to 60,000 shells.

The main effort is to push back our forces from Donetsk," he wrote in a post on Tuesday evening.

Several Ukrainian cities were attacked on Wednesday, The New York Times reports, citing Ukrainian local leaders.

In the south, Ukrainian positions in Mykolaiv were attacked by air.

The port is said to have been damaged, and a civilian university is also said to have been hit.

Several homes are also said to have been destroyed in Odessa, where three people were injured.