Tripoli, Dec 25 (IANS) Libya Dawn militias killed at least 18 soldiers and damaged an oil tank during an attack against an army battalion in the northern city of Sirte Thursday, officials said.

An army source said that fighters of Libya Dawn and Ansar al-Sharia groups launched the surprise attack against guards of a power plant west of Sirte, some 500 km east of the capital Tripoli, Xinhua reported.

Some 14 killed soldiers belonged to the army’s Al-Jalet 136 Infantry Battalion, many of whose staff came from the same tribe of the renegade major general, Khalifa Haftar, who has led a military operation since May to “cleanse the country of terrorism”.

Witnesses said the clashes, still going on, broke out around the steam power plant in Al-Gbeba area, about 30 km west of Sirte, between the battalion, which was backed by armed Furjan tribesmen against Libya Dawn, and Ansar al-Sharia fighters.

Last week, Libya Dawn militias carried out an operation “to liberate oil fields and ports” in the oil crescent, an area along Libya’s northern coast between the second largest city Benghazi and Sirte, including the ports of Sidra, Ras Lanuf and Brega, the largest Libyan oil port. The oil crescent contains country’s most oil reserves.

Libya Dawn claimed that they are commissioned by the outgoing General National Congress. Its operation leader, Tarig Shnena, was killed in an air raid by Haftar’s air force.

Since Dec 13, the battles have slashed Libya’s oil production from 800,000 barrels per day to about 200,000 barrels, causing a loss of billions of US dollars to its general budget, according to Libyan officials.