The Denver Police Department has issued a warrant for the arrest of former UFC fighter Melvin Guillard after he was allegedly involved in a bar fight early Monday morning.

On Friday, TMZ posted footage showing a man resembling Guillard knocking down two men with punches, with one of the victims appearing to lose consciousness.

Per TMZ, the incident occurred at a Denver bar just before 2 a.m.

Guillard, 35, has spent the majority of his fighting career in mixed martial arts. He participated in the Ultimate Fighter 2 and ultimately secured a spot in the UFC. Guillard went 12-9 with one no-contest in 22 UFC fights before being released in 2014.

He is 32-21-2 in his MMA career and is winless in his last nine bouts.

Guillard has also participated in bare-knuckle fighting in recent years.