Gunmen have killed at least 15 Libyan soldiers in an attack on a checkpoint near the city of Bani Walid, a former stronghold of supporters of Muammar Gaddafi, the country's former leader, according to officials.

"The ambush happened on the road between Bani Walid and the town of Tarhouna, where the army had a checkpoint," Ali Sheikhi, a spokesman for the army joint chief of staff, said on Saturday.

"They came under heavy gunfire. Between 12 and 15 soldiers were killed."

Army Captain Hassan al-Saidah said 15 soldiers had been killed and five wounded in the attack, which forced officials to close the main road to Bani Walid. The Libya News Agency says another five soldiers were wounded.

No stability

Officials did not say who might be responsible for the ambush. Clan and tribal rivalries, as well as armed groups, have flourished in the absence of strong central government and Libya's armed forces cannot fully maintain order.

The country has been hit by a months-long wave of attacks targeting military officers, activists, judges and security agents. 

Bani Walid was one of the last strongholds for supporters of dictator Gaddafi in the country's 2011 civil war, and was besieged again by pro-government militias last year.

Two years after Gaddafi was overthrown and killed in a civil war, the north African country's fragile central government is struggling to control rival militias competing for influence in the aftermath of the conflict.

Source: Agencies