TRIPOLI, Dec. 26 (Xinhua) -- Unknown gunmen on Tuesday blew up an oil pipeline in eastern Libya, causing a possible drop of crude oil production of 70,000 to 100,000 barrels per day, according to the state-owned National Oil Corporation.

"An explosion hit the oil pipeline of Zaqut-Sidra of Al-Waha Co., which connects the oil fields and Sidra oil port," the corporation said in a statement.

"Fire detection teams of Al-Waha Co. went directly to the site to deal with the fire, which reached a diameter of 15 meters. Support teams from the neighboring Raquba field also rushed to the site. The affected area was isolated from the nearest valve," the statement added.

A source of the corporation said the explosion is likely to be "a subversive act by an armed group," adding "the explosion was done by planting explosive devices on both sides of the pipeline."

No groups have claimed responsibility for the attack so far. The source did not rule out possibility for involvement of IS militants, who previously claimed responsibility for similar attacks in the region.

A source of the Oil Installations Guards told Xinhua that security patrols had monitored movements of armed vehicles on a nearby desert road.

"Security operations are carried out on a wide scale in order to track the armed vehicles, which may belong to the attackers," the source confirmed.

The oil crescent region, some 500 km east the capital Tripoli, contains the country's largest oil ports.