A retired Russian commander behind strikes that claimed 8,000 Ukrainian lives has been killed by a 'suicide bomber' on the southern city of Stavropol.
Russian authorities have now opened a criminal case following the death of the two men.
Retired Russian commander Zaur Gurtsiev was killed on Thursday following a blast in Stavropol.
Russian authorities did not say what caused the explosion, but did not rule out the possibility of Ukraine's involvement.
In December, the head of the Russian military's biological and chemical weapons unit Lt. General Igor Kirillov was killed along with his deputy in an explosion in Moscow.
Last month, an explosive device in Moscow killed senior Russian General-Lieutenant Yaroslav Moskalik.
Meanwhile, a Russian bombing campaign that had escalated in recent days slowed overnight, with far fewer Russian drones targeting Ukrainian towns and cities. »