A Filipino nurse has been kidnapped and gang-raped in the Libyan capital of Tripoli.

The woman was seized outside her residence on Wednesday and taken to an unknown location, where she was sexually abused by up to six men, the Philippines' Foreign Affairs spokesman Charles Jose told reporters.

She was released about two hours later and taken to hospital for treatment.

The incident took place only a few days after a Filipino construction worker was beheaded, amid allegations he was killed for not being a Muslim.

Following the latest incident, the Filipino government called for the evacuation of its 13,000 citizens in Libya, which has been rocked by violence in the last few months.

"We reiterate our call to our remaining nationals in Libya to immediately get in touch with the Philippine embassy in Tripoli and register for repatriation," said a foreign department advisory note issued on Thursday.

Libyan rebels have been fighting against government forces over the control of oil production. The rebels seized several ports last year and threatened to start selling oil independently unless they obtain a greater share of oil revenues and autonomy from Tripoli.

Libya's government called for international help after some oil storage tanks were set on fire in July.

The fire was started after one of the tanks was hit by a rocket. The state-owned National Oil Corp (NOC) warned of the possibility of an environmental disaster.

A few days later, militiamen took control of a key special forces base in Benghazi after a battle that killed at least 38 people.

Shortly after, the extremists declared Benghazi an "Islamic Emirate", claiming total control of the city.

The Libyan government has been struggling to contain the rebels' insurgence since leader Muammar Gaddafi was toppled in 2011.