A missile fired from an unmanned military drone killed six heavily armed Iraqi insurgents in Baghdad Thursday, U.S. military officials reported.

Coalition forces operating the drone fired the Hellfire missle on a large group of criminals with rocket-propelled-grenade launchers and a mortar tube, according to a U.S. Department of Defense press release.

Soldiers also used drones in at least two other incidents in Iraq Thursday, the release said.

An aerial weapons team used a drone to spot three men returning to a potential rocket site in northeastern Baghdad. The team confirmed the presence of three rockets at the site and then destroyed them with a Hellfire missile as well as two other missiles at another site a short time later.

In a separate event, a drone showed a rocket lauch site and positively identified a vehicle used in the attack. The drone then struck the vehicle with a missile.

Iraqi soldiers also discovered more than 30 bodies in a mass grave at a house in Mahmudiyah on Thursday. Initial reports indictate the remains had been buried for more than a year. The entire house was declared a grave site and the Iraqi army is excavating the area.