A tanker has loaded 600,000 barrels of crude from storage at the Libyan port of Hariga, an energy official said, the first vessel to pick up oil for export from the country in more than a week.

The official said crude supplies from the Sarir oilfield, which flow to Hariga for export, remained disrupted following a pipeline blast, with repairs and maintenance expected to take a number of days.

Libya's oil exports, on which the North African country's revenues depend, have collapsed as fighting among factions has split the nation. The shortfall helped raise the price of benchmark Brent oil to a 2015 high of $63 a barrel this week.

Hariga is the only operating oil port, though two small offshore platforms can also export around 70,000 to 80,000 barrels per day (bpd) of crude.

No oil tankers departed Libya in the previous week, industry sources said and ship-tracking data showed. Production has slipped to less than 200,000 bpd, well below 1.6 million bpd before the country's 2011 civil war and down from 900,000 bpd in October, with most output going to feed the Zawiya refinery near Tripoli.

Four years after the NATO-backed war toppled leader Muammar Gaddafi, Western governments fear Libya is sliding deeper into conflict as rival factions battle for control and the country's oil wealth.

The worsening situation, including the rise of a group linked to Islamic State militants that beheaded 21 Egyptian Christians, has prompted international energy firms to withdraw staff from the country.

Italian state-controlled Eni, the biggest foreign oil producer by volume in Libya, said on Tuesday it had withdrawn all expatriate employees apart from those working offshore, though some oil and gas production was continuing.

The Libyan official said the tanker that loaded at Hariga was due to sail to Italy. Reuters, using tanker-tracking data, was not immediately able to identify the vessel. Some ships turn off their satellite transponders when entering Libyan ports. - Reuters