The information minister of Libya's rebel movement said its forces have overrun the base of a rival faction after five hours of fighting.
Mahmoud Shamam said the clashes broke out at around 3am early on Sunday and left four rebels dead and six wounded.
The main rebel force was now in control of the al-Nidaa Brigade's base on the western outskirts of Benghazi, the de facto capital of Libya's rebel-held east.
The fighting followed Thursday's killing of chief rebel commander Abdel Fattah Younes in yet unexplained circumstances.
The killing and clashes point to sharp divisions within the rebel movement nearly six months after the start of the uprising against Muammar Gaddafi's rule.
Younes was Gaddafi's interior minister before defecting to the rebel side.