Oil exports were halted in January by eastern forces, cutting off Libya's main source of revenue [File: Ismail Zitouny/Reuters]
Libya's National Oil Corporation (NOC) said Russian and other foreign mercenaries entered the Sharara oilfield, adding it completely rejects "attempts by foreign countries to prevent the resumption of oil production".
On Friday, the NOC said the mercenaries entered Sharara in a convoy of vehicles and met with representatives of the Petroleum Facilities Guard (PFG), a force established to maintain security at the oilfields.
Libya has been effectively divided since 2015 between areas held by the internationally recognised Government of National Accord (GNA) in Tripoli and a rival administration in Benghazi.
Oilfields and export facilities are mostly located in the territory controlled by the eastern-based self-styled Libyan National Army (LNA), led by renegade military commander Khalifa Haftar.
An international agreement says that oil can only be exported by the Tripoli-based NOC, with payments going to the Central Bank of Libya there.
The LNA, backed by Russia, the United Arab Emirates (UAE) and Egypt, suddenly lost this month much of its territory around Tripoli and the northwest to the GNA, backed by Turkey.
Oil exports were halted in January by eastern forces, cutting off Libya's main source of revenue. After the GNA made gains this month, the NOC attempted to restart production at Sharara and El Feel Field.
In a statement, NOC chairman Mustafa Sanalla, said: "Some [countries] cynically express their public regret for Libya's continued inability to produce oil while all the time working in the background to support blockading forces."
The front lines in Libya have stabilised over the past two weeks west of Sirte, a central coastal city that is the closest to the main oil export terminals.
SOURCE: Reuters news agency