Fighting between armed factions allied to Libya’s competing governments broke out yesterday near the country’s main border crossing to Tunisia, Libyan and Tunisian officials said yesterday.

Meanwhile later in the evening Libya declared force majeure for the country’s two biggest oil exports ports, Es Sider and Ras Lanuf.

The Tripoli-based state National Oil Corp (NOC) said in a statement that oil production flowing to the two eastern ports would be gradually shut down, blaming clashes nearby between armed factions allied to Libya’s two rival governments. Only a minimum oil staff would stay on site.

Force majeure is a legal waiver for contractual obligations.

Libyans have fewer options to travel abroad as two Libyan state carriers also say they have halted flights out of Tripoli and Misurata to Istanbul

The Opec oil producer is caught in a conflict between two governments and parliaments since a group called Libya Dawn seized Tripoli in the summer.

The recognised government has been forced to work out of the east. In recent weeks it has sought to regain ground in the west with air strikes and the use of allied troops from the Zintan area calling themselves the Libyan National Army (LNA).

An armed security guard stands in front of a police station in Benghazi. Photos: Reuters

Omar al-Sanki, Interior Minister of the recognised government, said his forces had seized the western Ras Jdir border crossing, the main gateway into Tunisia. But a Libyan border official and the mayor of Zuwara, a town east of Ras Jdir, denied this.

“Our forces... are still in control of Ras Jdir and it is not true that the borders have been taken by the army of tribes – LNA,” said the mayor, Hafed Juma. He said war planes belonging to the eastern-based government had attacked their positions, killing four people.

A Tunisian security source said there was fighting in the Libyan area of Boukamech near Ras Jdir. The border station was open, though Tunisia had advised its citizens to avoid the crossing.

In another setback for travellers, two Libyan state carriers said they had halted flights out of Tripoli and Misurata to Istanbul after the EU imposed an overfly ban last week. Egypt and Tunisia had already banned flights from western Libya, leaving Libyans with few options to travel abroad.

Western powers fear the conflict between former rebels who helped topple Muammar Gaddafi in 2011 will spiral out of control.

On Saturday, a force allied to the Tripoli government tried taking the eastern Es Sider oil export port, triggering air strikes from the eastern government and a shutdown of the terminal. Libya’s eastern Es Sider oil export port, which was shut yesterday, is Libya’s biggest export port.

Air strikes on Saturday by forces loyal to Libya’s recognised government hit targets near the port, aiming to stop an advance by troops of the rival administration in Tripoli seeking to take control of oil facilities in the country’s east.

Clashes were continuing near Es Sider, Tripoli-based al-Nabaa television station said yesterday, adding that a force allied to the government in the capital was at the gates of the terminal. A worker said staff had left the site for security reasons.

The company had been producing around 200,000 barrels a day, data from the State-run NOC showed earlier this month. NOC had previously put the OPEC member’s output at around 755,000 bpd, though this included some 140,000 bpd of refined products partly consumed locally.

Libya’s oil industry had seen a modest recovery from a wave of protests until last month, when the 340,000-bpd El Sharara oil field in the south closed due to clashes and a pipeline closure.

The fighting near the Es Sider port is part of a struggle in the North African country between competing governments allied to armed factions three and a half years after the ouster of Muammar Gaddafi.