Ukrainian defence authorities have said that a top Russian general was killed during fighting near the country's second largest city of Kharkiv.
In a statement on Monday night, the Defence Intelligence of Ukraine identified the slain general as Vitaly Gerasimov, who was a major general, chief of staff and first deputy commander of the 41st Army of the Central Military District of Russia.
According to the statement, Gerasimov took part in the Second Chechen War which took place from August 1999 to April 2000, and the Russian military operation in Syria.
"He received a medal for the return of the Crimea," it said.
The Defence Intelligence further said that "data obtained also indicate significant problems with communication in the occupier's army and with the evacuation of their broken units".
"A number of senior Russian army officers were also killed and wounded," the statement added.