Ukrainian forces shell Russian-controlled Donetsk, officials say

Russia-Ukraine War: "At exactly 7.00 o'clock this morning they subjected the center of Donetsk to the most massive attack since 2014," Alexei Kulemzin said.

Ukrainian forces shelled the Russian-controlled eastern Ukrainian city of Donetsk overnight in some of the biggest attacks for years, Russian-installed officials in the annexed areas said on Thursday.

Russia-Ukraine War: Workers repair power lines in the town of Lyman, Donetsk region. (AFP)

"At exactly 7.00 o'clock this morning they subjected the center of Donetsk to the most massive attack since 2014," Alexei Kulemzin, the Russian-backed mayor of the city, said on Telegram.

"Forty rockets from BM-21 Grad multiple rocket launchers were fired at civilians in our city," Kulemzin said. He cast the attack as a war crime.

Reuters was unable to immediately verify battlefield accounts from either side.