At least 12 civilians were killed and at least 40 others were injured when Russian artillery shells hit the town of Severodonetsk, local officials said.
Sergiy Haidai, the governor of Lugansk, accused the Russian armed forces of bombing houses via Telegram.
The Russian army and pro-Russian separatists are attacking the city from virtually all sides.
It is impossible to verify the number of victims of the war, which lasts almost three months. Both Kyiv and Moscow rarely report casualties to their armed forces.
Last week, pro-Russian separatists in Danieck reported that 1,700 of their fighters had been killed. The most recent report released by the Russian Ministry of Defense was at the end of March, which spoke of 1,351 dead. In mid-April, Ukrainian President Volodymyr Zelensky spoke of 3,000 Ukrainian military dead. To date, the UN says it has confirmed more than 3,800 civilian deaths.
The toll of war victims is certainly considered to be much heavier in reality.