An assault on the Libyan interim government headquarters has left one guard dead and several others wounded, according to reports.
Fighters attacked and surrounded the building on Tuesday, demanding stipends that the government promised to pay to those who helped oust former leader Muammar Gaddafi.
Nasser al-Manaa, an interim government spokesperson, said the armed protesters, some of them carrying mortars, tried to push their way into the building.
The building was evacuated as the firefight with the security guards ensued, leaving one guard dead and four wounded, he said.
"Many men encircled the building and opened fire against it with weapons including anti-aircraft cannons," a government employee present during the attack told the AFP news agency.
Several lorries mounted with anti-aircraft guns surrounded the building in central Tripoli, blocking traffic, witnesses said.
Abdurrahim el-Keib, the interim prime minister, was in the building meeting with his defence minister at the time of the attack, a person who was also inside said on condition of anonymity, fearing retribution. The prime minister was not hurt.
Al Jazeera's Omar al Saleh, reporting from Tripoli, said the rebels came from the Nafusa mountains to surround the building.
He said the decision by the interim government to halt stipends, citing "mass corruption and fraud", angered the former fighters.
"I did speak to the son of the Libyan finance minister who said his father was at the building at the time of the attack," our correspondent said.
The fighting lasted between one and two hours with heavy ammunition being fired, he said.
The headquarters has previously been attacked, but our correspondent said that one of the fighters he spoke to described Tuesday's attack as the most serious.
Al-Manei said some of the several hundred protesters were demanding their delayed salaries while others demanded compensation for the wounded and more efforts to locate those missing since the civil war last year, and earlier in Gaddafi's prisons.
"We didn't stop giving salaries, but we have postponed (paying) salaries so we can apply a new mechanism that ensures no corruption is involved and no money is wasted" on fake claims, al-Manei told reporters.
Khaled Bshair, the commander in charge of the security guards at the prime minister's office, said 14 armed men were arrested and were under investigation.
He said some of the protesters were unarmed but accused unidentified parties of trying to incite violence.