A bomb blast in a Moscow residential complex killed Armen Sarkisyan, leader of the pro-Kremlin Arbat Battalion, early Monday.

The explosion also killed his bodyguard and injured five others.

Russian authorities are investigating, with reports suggesting the attack was planned.

Sarkisyan, originally from Armenia, led a paramilitary unit fighting for Russia in Ukraine and was wanted by Ukraine for past violence, The Moscow Times has reported.

Kyiv recently named him in a probe into Russia’s recruitment of prisoner fighters.

Written by B.C. Begley