It was not immediately clear whether the explosion was an act of sabotage.

The truck caught fire and flipped on its side as it exploded on Wednesday. Four fire engines arrived and were battling the flames. Residents attacked foreign reporters who rushed to the scene and chased them back to a nearby hotel where many of them are staying.

Qaddafi, Libya’s ruler of 41 years, has already lost the eastern half of the country to rebels backed by army troops who had defected. There are several towns near Tripoli that also fell in rebel hands.