Flames engulfed a university building's wooden roof in Donetsk following Ukrainian shelling on Saturday, said an emergency official in the Russia-controlled city in eastern Ukraine.
"As a result of the latest attack on Donetsk, the first building of the University of Economics and Trade is on fire," Alexei Kulemzin, the Russia-installed mayor, said on Telegram.
"We are using 12 water tanks, three ladders and 100 fire fighters," said Alexei Kostrubitsky, the Russia-installed emergency minister for the region that Moscow calls the Donetsk People's Republic.
"The whole roof is on fire."
Alleged use of cluster munitions by Ukrainian forces
Kostrubitsky said Ukrainian forces used cluster munitions in the shelling that caused the blaze. Reuters could not independently verify the information. Both sides have used cluster munitions in the course of Russia's 17-month invasion of Ukraine.
Ukraine, which received supplies of US cluster munitions last month, has vowed to use them only to dislodge concentrations of enemy soldiers.
There was no immediate comment from Ukraine on the alleged shelling. Both sides deny targeting civilians and civilian infrastructure.
Kostrubitsky said there were no people inside the building during the shelling.
"The most difficult thing is that the roof is wooden, so the fire spreads fast."
Russia's RIA state news agency cited Kostrubitsky and emergency services as saying the fire spread to an area of about 1,800 sq m (19,400 sq ft) before being contained early on Sunday.