Libya threatened Saturday to bomb a North Korean-flagged tanker if it tried to ship oil from a rebel-controlled port, in a major escalation of a standoff over the country's petroleum wealth, Alarabiya reported.
Libyan rebels blockading the terminal in eastern Libya had been trying to load crude aboard the ship.
They seized three major Libyan ports since August to press their demands for more autonomy, and warned Tripoli against staging an attack to halt the oil sale after the tanker docked at Es Sider export terminal, one of the country's biggest.
A local television station controlled by protesters showed footage of pro-autonomy rebels holding a lengthy ceremony and slaughtering a camel to celebrate their first oil shipment. In the distance stood a tanker.
Prime Minister Ali Zeidan appeared hours later on television to warn the tanker's crew. "The tanker will be bombed if it doesn't follow orders when leaving (the port). This will be an environmental disaster," Zeidan said.
"They are now trying to load oil," he said, denouncing it as a criminal act. Authorities have ordered the arrest of the tanker's crew.
There was no immediate sign of the country's armed forces moving towards the port. Analysts say the military, still in training, would struggle to overcome rebels battle-hardened from the eight-month uprising against Muammar Qaddafi.
Deputy Defence Minister Khaled al-Sherif told AFP a "crisis committee" made up of government officials and lawmakers had issued an ultimatum for the ship to leave Libyan territorial waters.
"If the ship doesn't comply, it will be bombed by the air force or intercepted at sea by the navy," Sherif said.
An MP and committee member said the deadline 2:00 pm (1200 GMT) deadline had expired without any action being taken.
The latest crisis erupted in July, when security guards at key oil terminals shut them down, accusing the authorities of corruption and demanding a more equitable distribution of oil revenues.
The situation has become more complicated as self-rule activists in the east have insisted on the right to export.
Saturday's incident was the latest in a standoff between the government and militants over exports, which are the principal source of revenue for the North African country.
In January, the navy prevented two tankers docking in Al-Sidra to take on crude. The government even threatened to bomb any ships attempting to dock without permission from the National Oil Corporation.
Following the blockade, production plunged to around 250,000 barrels per day from 1.5 million bpd, and the economy ministry estimated the treasury has lost more than $9 billion (6.5 billion euros) in revenue.
Production has since recovered to 546,000 bpd, but the crisis has taken its toll.