Libyan rebels say they have captured the coastal town of Bin Jawad after several days of fighting with fighters loyal to Moammar Gadhafi.

The anti-Gadhafi forces say they seized the town on Sunday. Bin Jawad is about 520 kilometers from 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.

Meanwhile, human rights groups say evidence indicates pro-Gadhafi forces killed at least 17 detainees and arbitrarily executed dozens of civilians as rebels moved into Tripoli.

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

On August 26, Human Rights Watch found 18 bodies near a government building close to one of Moammar Gadhafi's compounds. The rights group says witnesses reported Libyan government forces killed the 18 earlier in the week.

HRW said two of the victims had their hands tied behind their backs, while two more were wearing the green scrubs of Libyan doctors and nurses.

The rights group also found 29 bodies in and around a field clinic where it says “there were signs that Gadhafi loyalists had been present.”

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 forces loyal to Mr. Gadhafi during efforts to advance into Zuwarah, where a major supply route to Tripoli is located.