TRIPOLI, Libya — Rival militants clashed in the Libyan capital Sunday, killing three people, officials said, in the latest example of the challenges facing the country's new rulers in uniting armed militias and overcoming long-standing tensions among them.

Since fighting began last week in Tripoli, five people have been killed, a hospital official said.

The battles have pitted fighters from the town of Gharyan, 80 kilometres south of Tripoli, against a militia from al-Asabia, about 16 kilometres to the southwest, said Ashraf al-Aswad of the Gharyan hospital. They resumed a day after tribal leaders travelled to Tripoli for reconciliation talks.

He told The Associated Press that 50 people were wounded on Sunday, and heavy weapons, including mortars, were used in the fighting.

The clashes have underscored the tenuous security situation in the North African nation since revolutionary forces overthrew longtime dictator Moammar Gadhafi last year after eight months of civil war.

Libya's new leaders are still struggling to rein in the various militias that played a key role in toppling Gadhafi but have largely refused so far to disarm or submit to the interim government's authority.

Ahmed al-Sharif of the Gharyan militia said his fighters went to arrest people suspected of having ties to the former Gadhafi regime. Al-Asabia fighters refused to hand the suspects over, triggering a shootout. The two sides fired guns and rockets at each other.