Libyan authorities foiled an attempt by saboteurs to set ablaze oil wells south of the capital at dawn on Sunday and arrested six Libyan suspects, a security official told AFP.

Two Libyan guards deployed to protect oil installations security official were slightly wounded in the operation at 1:30 am (2330 GMT Saturday) at the Sarir oilfield, the official said.

"A group of employees who work at the Sarir oilfield set on fire an administrative building and damaged" other facilities, including a restaurant and dormitories, the official said.

"The saboteurs also tried to set oil wells alight, but guards tasked with protecting oil facilities arrested them," he said, adding that those captured were six people who were identified and are being interrogated.

According to the official, two of those arrested had in their possession "some rifles" and other weapons.

"Initial results of the investigation show that this gang received its weapons from outside Libya and got its instructions through the Internet," the official said.

Libya has been swept by anti-government protests, with demonstrations taking place mostly in the restive east of the country.

Libyan security forces clashed with anti-regime demonstrators in the city of Misrata, 200 kilometres (120 miles) from Tripoli on Sunday, as protests spread closer to the capital, witnesses told AFP by telephone.

At least 104 people have been killed in a crackdown by the security forces on anti-regime protests raging in the east of the country since Tuesday, Human Rights Watch said on Sunday, citing medics and witnesses.

OPEC member Libya is Africa's third-largest oil producer after Nigeria and Angola, pumping close to two million barrels a day, and has estimated reserves of 42 billion barrels.