The missiles, four to six-feet long and Russian-made, can weigh just 55 pounds with launcher. They lock on to the heat generated by the engines of aircraft, can be fired from a vehicle or from a combatant’s shoulder, and are accurate and deadly at a range of more than two miles.

Peter Bouckaert of Human Rights Watch first warned about the problem after a trip to Libya six months ago. He took pictures of pickup truckloads of the missiles being carted off during another trip just a few weeks ago.

“I myself could have removed several hundred if I wanted to, and people can literally drive up with pickup trucks or even 18 wheelers and take away whatever they want,” said Bouckaert, HRW’s emergencies director. “Every time I arrive at one of these weapons facilities, the first thing we notice going missing is the surface-to-air missiles.”