The mayor of the Ukrainian city of Kharkiv has reported four attacks (file image). (EPA PHOTO)
Three explosions have been heard, then electricity cut out in Ukraine's second city of Kharkiv, a Reuters witness reports.
"There are no lights in some parts of the city. Information about casualties is being specified," Kharkiv Mayor Ihor Terekhov said in his Telegram channel.
He also reported a fourth attack.
Terekhov said an infrastructure facility was hit and that authorities were working to restore power as quickly as possible.
The report followed a rocket attack on Kharkiv on September 9 in which at least 10 people were wounded.
Ukrainian officials said that attack was revenge for its forces' successes on the battlefield against Russia.
Australian Associated Press
