U.S. soldiers fire an M198 howitzer LCpl Samantha L. Jones/USMC ISIS militants may be in a position to pummel other cities in Iraqi army control after capturing American-made weapons the group seized from the Iraqi military, Mitchell Prothero reports for McClatchy DC.

During ISIS's blitz across northern and central Iraq last month, the group captured upwards of 52 155mm M198 howitzers.

These U.S.-supplied artillery pieces have a range of up to 20 miles and can also be outfitted with GPS aiming systems. The howitzers' range could place Baghdad, as well as many other major Iraqi cities, squarely within bombardment range of ISIS.

Jeremy Binnie, an analyst for British military consultancy HIS Janes, told McClatchy DC that he doubted the Islamists would be able to learn how to use the GPS aiming systems quickly. However, the weapons can fire two rounds a minute and could still cause considerable damage to cities through imprecise fire.

“They shouldn’t have too much trouble shelling large area targets like a city if they have sufficient ammo," Binnie said.

ISIS currently maintains a stronghold in the city of Fallujah, only 40 miles to the west of Baghdad. The group has also made gains to the south of Baghdad in the area Jurf al Sakhar, which is only 13 miles from the Shiite holy city of Karbala.

Should ISIS blindly shell Karbala, Iraq could plunge even further into a sectarian civil war between Sunnis and Shias. ISIS has also attempted to shell at least twice so far the golden-domed Samarra Shrine, whose destruction in 2006 set off a terrible cycle of violence.

Aside from the 52 howitzers, ISIS also took 1,500 U.S.-made Humvees and 4,000 PKC machine guns that can fire upwards of 800 rounds per minute.