Russian forces killed two people and wounded nearly two dozen others - including two children and a pregnant woman - in separate attacks, Ukrainian officials said Tuesday.

A married couple aged 45 and 48 were killed in Sloviansk in the eastern Donetsk region, a key prize for the Kremlin, which has concentrated its firepower there.

Their 20-year-old son survived the attack in the region the Kremlin claims to have annexed, local prosecutors said.

A Russian drone barrage meanwhile wounded nearly two dozen people in the southern city of Odesa, the governor said.

The Black Sea city key for Ukrainian exports has been pummeled routinely by Russian forces since they invaded Ukraine nearly four years ago.

The governor said Russia had launched more than 50 attack drones on the region, damaging dozens of residential buildings, a church and schools.

"Nine people have been hospitalized, including two children (girls born in 2013 and 2008) and a pregnant woman at 39 weeks," Governor Oleg Kiper said on social media giving the wounded toll of 23 people.

He added that rescue workers had freed 14 people from the rubble but that more may be trapped underneath.

Russian drone and missile attacks have recently knocked out power, lighting and heat to millions of Ukrainians across the country.