Forces loyal to Muammar Gaddafi have seized control of a Libyan town and raised the ousted regime's green flag.
The retaking of Bani Walid came as Libya's new leaders struggled to unify the oil-rich North African nation three months after Gaddafi was captured and killed.
Hundreds of well-equipped and highly trained remnants of Gaddafi's forces raised the green flag over buildings in the western city late on Monday after hours of clashes, said Mubarak al-Fatamni, the head of Bani Walid local council.
Mr al-Fatamni, who fled to the nearby city of Misrata following the attack, said four revolutionary fighters were killed and 25 others were wounded. He said the Libyan Defence Ministry has not sent any forces to the area.
A top commander of a revolutionary brigade in Bani Walid, Ali al-Fatamni, who was present in Benghazi during the attack, said he has lost contact with other fighters in the town.
The bold attacks, which have led authorities to declare states of emergency in several areas, are the latest breakdown in security, three months after Gaddafi's capture and killing. Protests have surged in recent weeks, with people demanding that the interim leaders deliver on promises of transparency and compensation for those injured in the fighting.
Bani Walid, 90 miles south-east of Tripoli, was one of the last Gaddafi strongholds to fall to revolutionary forces amid a months-long civil war. Gaddafi's son and longtime heir apparent, Saif al-Islam, was long believed to have been hiding in the town.
Saif, who has been charged with crimes against humanity by the International Criminal Court, was captured in November by fighters from the town of Zintan in Libya's western mountains, who continue to hold him.