Russian missiles and artillery fire in northeast and southern Ukraine killed at least three people on Saturday, law enforcement agencies said.

"Around 3:15 in the morning, the enemy launched a missile attack on the town of Barvinkove, in Izium district," the northeast Kharkiv region's prosecutor's office said in a statement.

It listed the dead as two men aged 48 and 69 and said around 50 buildings were damaged in the strike, apparently by three Russian Iskander missiles.

Another strike hit an agricultural business in the village of Oleksiivka, it said, though there were no reported casualties.

Separate artillery shelling later in the day killed a 44-year-old man in the city of Nikopol, in the south of the country, national police said.

Ukrainian President Volodymyr Zelensky has been urging his nation's allies to step up air defence support to be able to intercept Russian missiles and drones raining down daily on the country over nearly 30 months of conflict.

The death toll in a Russian strike Friday on a playground in the southern city of Mykolaiv rose to four, including one child, with 24 injured, its mayor Oleksander Senkevitch posted on Telegram.