Staff at Libya's Waha Oil Company go on strike to protest against the sale of oil to a North Korean-flagged tanker at the Es Sider port, in Tripoli, on March 9, 2014. Picture: Ismail Zitouny

Tripoli - US forces in the Mediterranean Monday took control of a tanker that had loaded crude oil at Libya's rebel-controlled eastern terminal of Sidra, the Department of Defense said.

A team of US navy special forces boarded the ship in the early hours of Monday in international waters southeast of Cyprus, the department said.

The tanker docked in Sidra earlier this month as federalist rebels in Libya's east announced they would start exporting oil, ignoring threats by the government.

“No one was hurt tonight when US forces, at the request of both the Libyan and Cypriot governments, boarded and took control of the commercial tanker Morning Glory, a stateless vessel seized earlier this month by three armed Libyans,” the Pentagon said in a statement.

The Libyan government had said the tanker flew the North Korean flag. North Korea last week said the ship had been removed from its registry.

“The Morning Glory is carrying a cargo of oil owned by the Libyan government National Oil Company. The ship and its cargo were illicitly obtained from the Libyan port of As-Sidra,” the US statement added.

The tanker will head to a port in Libya with a team of US sailors supervising the transit, according to the statement. The Libyan government confirmed that the tanker had been captured, adding that the crew were safe and “will be dealt with in accordance with the relevant national and international laws.”

“The government expresses its thanks and esteem to all those who participated in affirming the sovereignty of the Libyan state, and in particular its international partners, foremost among them the governments of the United State of America and the Republic of Cyprus,” it said in a statement published on its website.

The federalists' move to export the oil sparked a crisis with Tripoli over Libya's eastern oil ports, controlled since July by renegade guards, prompting parliament to remove Premier Ali Zeidan from office through a no-confidence vote.

Federalists, who in 2012 unilaterally declared autonomy in the eastern region of Barqa, or Cyrenaica, demand that oil revenues be kept within the region.

Libya's oil exports, the mainstay of the North African country's economy, plummeted after the Petroleum Facility Guard force responsible for protecting the eastern terminals began blockading them in July.

Monday's government statement warned that “oil is the backbone of the national economy and that any interference with it. cannot be accepted or overlooked.”

But Justice Minister Salah al-Merghani, speaking in Benghazi, capital of Cyrenaica, appeared to rule out military action, saying: “Oil will not be a cause of harm to Libyans and is not worth a single drop of blood.”

National Congress President Nuri Abu Sahmain on Wednesday gave the federalists two weeks to hand back control of the ports or face military action.

Militias loyal to the congress last week drove the renegade guards out of the town of Sirte, halfway between Tripoli and Benghazi, but have not moved on the ports.

Meanwhile, seven soldiers were killed and nine people injured when a car bomb exploded at the gate of a military school in Benghazi, state news agency Lana reported quoting an unnamed senior security official.

State television reported that the explosion took place after the end of a graduation ceremony for army officers.

Benghazi City Council issued a statement blaming the interim government and the National Congress for what it said was their “negligence in protecting this city and inadequate funding for security plans.”

The country's interim government has been struggling to impose order since the fall of longtime leader Moamer Gaddafi in 2011.

Government troops are outnumbered by various militia groups, who helped topple Gaddafi but have since defied the country's interim rulers