Militants have seized two oil fields in central Libya.
Islamist militants are reported to have seized two oil fields in central Libya, as rival groups fight for control of the country.
Forces guarding the al-Bahi and al-Mabruk sites retreated after running out of ammunition.
Libya's internationally recognised government in Tobruk is locked in a bitter battle with rivals Libya Dawn, who control the capital, Tripoli.
The two sides also mounted airstrikes against each other on Tuesday.
"Extremists took control of the al-Bahi and al-Mabruk fields and are now heading to seize the al-Dahra field following the retreat of the forces guarding these sites," said Colonel Ali al-Hassi, a spokesman for the oil industry security service.
The sites had been closed for some weeks due to violence and a slow-down of exports.
A gun attack on the al-Mabruk site in February left 11 people dead.
Mr al-Hassi also said militia warplanes had made an unsuccessful attempt to attack an export terminal at al-Sidra oil port.
In response, the head of the internationally recognised government's air force said it had struck Tripoli's Mitiga airport, without causing any casualties.
Oil fields and airports are prime targets in the conflict, which has pitted Prime Minister Abdullah al-Thinni's parliament in Tobruk against Libya Dawn, an alliance of militias that includes various Islamist groups.
It took control of Tripoli last year and formed its own administration.
The United Nations is trying to restart negotiations to end the fighting that has engulfed Libya since the fall of Colonel Muammar Gaddafi in 2011.