Rival armed groups have clashed for hours across Tripoli, sending residents fleeing for cover and killing at least one person and wounding 12 in the worst fighting for months in the Libyan capital.

The second outbreak of street fighting within days shows how the government is struggling to contain the armed groups that helped overthrow Muammar Gaddafi two years ago but kept their guns after the NATO-backed uprising.

The clashes erupted after the leader of an armed group, Nuri Friwan, died from his wounds after he was shot on Tuesday at a checkpoint manned by fighters from Soug al-Jomaa, an eastern Tripoli district.

Dozens of armed men, some riding in pickup trucks mounted with anti-aircraft guns and others with rocket propelled grenades came from the western city of Misrata to avenge his death and attack a rival group in Tripoli, witnesses said.

Gunfire broke out while young people were enjoying a water pipe on the seafront and families were shopping or dining at the start of the weekend.

Toyota trucks mounted with anti-aircraft guns arrived in several parts of Tripoli, opening fire as they tried to storm Soug al-Jomaat, witnesses said. Panicked diners ran for cover, while drivers abandoned their cars.

The Radisson Blu, one of Tripoli's best hotels, evacuated some frightened guests after windows in the reception area were smashed by stray gunfire, an employee said.

Rival groups fired rocket-propelled grenades at the attackers from a bridge, witnesses said. Heavy shooting

could be also heard in at least three other districts close to the foreign ministry, state television building and embassies.

Gunmen were seen loading anti-aircraft guns mounted on trucks near the ministry.

Government struggles

When Libyan leader Mouammar Gaddafi was overthrown and killed in October 2011, the rebels were hailed as heroes for bringing an end to more than four decades of his rule.

But since then, they have formed armed groups with different ideologies and motivations.

Many factions have rejected the government's demands to turn in their weapons or join the national security forces, and a patchwork of armed groups effectively controls much of the country.

Libya's government is finding it harder to contain the former fighters in a country awash with weapons.