East Libyan forces have captured the final holdout of Islamist-led rivals in the southwest of Benghazi, ending weeks of resistance by fighters camped in a group of tower blocks.

The eastern-based Libyan National Army (LNA) has been waging a campaign in Libya's second biggest city for nearly three years and still faces pockets of resistance in two northern neighbourhoods, despite making big gains since early last year.

LNA spokesperson, Ahmed al-Mismari, said, "the heart of the terrorist organizations in the entire Eastern front" had been defeated.

Dozens of family members had also been in the besieged buildings and an unknown number were detained by the LNA. It was not immediately clear whether any of the LNA's opponents or their families had escaped.