Survivors and rights groups say pro-Gadhafi forces committed possible war crimes as rebels moved into the Libyan capital last week, killing scores of detainees and arbitrarily executing dozens of civilians.

Human Rights Watch said Sunday that its researchers have documented more than 110 corpses in four locations in Tripoli, many of whom appear to have been killed execution style either while in detention or with their hands bound.

The group's Middle East and North Africa director said the execution of detainees days before they would have been freed is a “sickening low” in the Libyan government's behavior.

A metal warehouse in a compound controlled until last week by Libya's elite Khamis Brigade contains about 50 scorched skeletons. A VOA correspondent who visited the warehouse says outside, another eight bodies lie on the grass, one with his hands tied behind his back. A survivor told VOA that as rebel forces approached, loyalist soldiers shot their prisoners, then tried to burn the bodies.

So far, there have been no specific allegations of atrocities carried out by rebel fighters. But it remains unclear who is responsible for some of the killings, including those of dozens of dark-skinned men whose bodies were found in two areas of Tripoli.

The gruesome discoveries come as rebels say they have captured the coastal town of Bin Jawad after several days battling fighters loyal to Moammar Gadhafi. The anti-Gadhafi forces say they seized the town on Sunday. Bin Jawad is about 520 kilometers east of the capital, Tripoli.

Rebels say they are surrounding Mr. Gadhafi's hometown, Sirte, and are negotiating with tribal leaders there for a peaceful surrender. Sirte is considered one place where the former leader may have fled to go into hiding. He has dropped out of sight since rebel fighters seized Tripoli.

A Red Cross ship entered Tripoli harbor Sunday carrying supplies for the city, which saw days of fighting between rebels and Gadhafi supporters last week. A VOA correspondent in Tripoli says the city has widespread shortages of medicine, drinking water and other basic supplies. Many areas are still without electricity.

On Saturday, Libyan rebels said they have gained control of a key border post near Tunisia, but were still fighting for control of the western city of Zuwarah.

Opposition fighters faced stiff resistance from Gadhafi loyalists during efforts to advance into Zuwarah, which is on a major supply route to Tripoli.