Putin speaks after Wagner Group leader Prigozhin dies in plane crash, says made 'serious mistakes'

Russia President Vladimir Putin spoke publicly Thursday about the plane crash on day earlier that killed Russian mercenary chief Yevgeny Prigozhin, saying he made some "serious mistakes."

Prigozhin initially led his mercenary Wagner Group in helping Russia in its war against Ukraine. But as the months went on, he became an outspoken critic of how Russia's Military ministry handled the battle. 

Some of Prigozhin top lieutenants were presumed dead in the firey plane crash that was widely seen as an assassination to avenge a mutiny that challenged Putin, according to the Associated Press. 

In total, seven passengers and three crew members were reportedly killed in the crash.

A preliminary U.S. intelligence assessment found the crash was intentionally caused by explosives, the Associated Press also reported Thursday.