Russian Deputy Defense Minister Dmitry Bulgakov has been dismissed from his post and transferred to "another post", the defense ministry in Moscow said on 24 September.
He will be replaced by Colonel-General Mikhail Mizintsev, who previously held the post of head of Russia's National Defense Control Center.
The Ukrainian military said Mizintsev led the siege of the port of Mariupol, which earned him the nickname "the butcher of Mariupol".
Mariupol was occupied by Russia in late May, after much of the city was reduced to rubble and thousands of civilians were killed during the siege.
The Russian military leadership under Defense Minister Sergei Shoigu has recently been criticized in circles close to the Kremlin.
About two weeks ago, the Russian army withdrew from Ukraine's eastern region of Kharkiv under pressure from a Ukrainian counteroffensive.
President Volodymyr Zelensky has declared that Ukraine has returned over 6,000 square kilometers of territory occupied by Russian forces.
The Russian invasion of Ukraine began on February 24.
As a result of the war, thousands of people have died and millions more have been displaced from their homes./REL