The toll from nightime Russian missile strikes on infrastructure including a five-storey residential building in the central Ukrainian city of Kryvyi Rig has risen to six, officials said Tuesday.
"Unfortunately, there are already six dead. The rescue operation is continuing," Oleksandr Vilkul, the head of the city's military administration, said in a statement on social media.
He added that six missiles had hit five civilian sites.
Four people were killed and 21 injured as a result of a strike on a five-storey apartment building, the emergencies ministry said.
According to a local official, who spoke to AFP on condition of anonymity, two more people died in a food storage facility that was also struck.
Sergiy Lysak, governor of the Dnipropetrovsk region that includes Kryvyi Rig, said 25 people were wounded, adding that some victims remained under the rubble.
Officials earlier said that three people had been killed.
Kryvyi Rig is the birthplace of Ukrainian President Volodymyr Zelensky.
Air raid sirens sounded across Ukraine as the capital Kyiv and the northeast city of Kharkiv also came under missile and drone attacks.
Ukraine's air force said Russia launched 14 cruise missiles and four Iranian-made drones overnight, with 10 missiles and one drone intercepted.
In the morning, another missile was fired by Russian forces before being shot down by the Ukrainian air defence.
"More terrorist missiles, Russian killers continue their war against residential buildings, ordinary cities and people. Unfortunately, there are dead and wounded," Zelensky said on Twitter.
The wave of attacks came after Ukraine claimed to have retaken seven villages and made advances in its counter-offensive against Russian forces.
Military spokesman Andriy Kovalyov said the area of the recaptured land in the eastern and southern regions amounted to "more than 100 square kilometres" (40 square miles).
The commander of Ukrainian ground forces, Colonel Oleksandr Syrskyi, said troops were continuing "the defence operation in the Bakhmut sector", scene of the longest battle of the offensive.
"Our soldiers are advancing, and the enemy is losing ground on the flanks," he said.
On Monday, Zelensky said Ukraine was making small gains in a "tough" counter-offensive.