According to Iraq’s Prime Minister Haider al-Abadi, ISIS have captured around 2,300 humvees which account for around two-thirds given to the Iraqi army by the United States.

Majority were captured when ISIS overran and took over Iraq’s second largest city of Mosul.

The humvees have been used to fight against Iraqi and Syrian forces.

“There’s a simple reason the militants are using Humvees and other armored vehicles as rolling bombs,” Sean D. Naylor reports for Foreign Policy. “Their protective armored plating prevents defenders from killing the trucks’ drivers before the militants can detonate their loads, while the vehicles’ capacity to carry enormous amounts of weight means the Islamic State can sometimes pack in a ton of explosives.”

ISIS have been using these humvees in suicide missions as well. They are loaded with explosives.

“There is little defense against a multiton car bomb; there is none against multiple such car bombs … the Islamic State is able to overwhelm once-thought-formidable static defenses through a calculated and concentrated use of suicide bombers,” The Soufan Group notes. “The Islamic State has neither a shortage of such explosives nor a shortage of volunteers eager to partake in suicide attacks.”