A Libyan rebel leader has accused the United States of behaving like pirates after US naval forces seized an oil-laden tanker that had sailed from a rebel-held port.
Ibrahim Jathran's defiant speech dampened hopes of a quick peaceful settlement with the government to end a blockage of three oil ports his men took over in summer to press for eastern autonomy and a greater share of oil revenues.
The conflict reflects wider chaos in Libya, where the government has been struggling to rein in militias that helped overthrow dictator Muammar Gaddafi in 2011 but kept their guns to become powerful political players.
On Sunday, US forces stormed a North Korean-registered tanker that had made it as far as the eastern Mediterranean off Cyprus after loading crude at the Es Sider port, one of three Jathran's men have occupied, and eluding Libyan government forces off-shore. The ship is on its way back to a government-controlled port.
Tripoli has given Jathran's group two weeks to clear the ports or face an offensive to end the blockage, which has crippled the country's finances.
But in a speech broadcast by a rebel television station, Jathran did not mention a government offer to hold new talks and said his group would continue its struggle. He called on the United Nations and Arab League to intervene to help the people of eastern Libya.
Jathran defended his repeated attempts to bypass Tripoli in selling oil. "We declare and confirm that, indeed, the majority of Libyan tribes have agreed to the necessity of taking hold of our resources for the benefit of the people," he said.
While Jathran's oil sale proved unsuccessful this time, the episode led to the dismissal of Libyan Prime Minister Ali Zeidan, who fled to Europe last week.
Western powers, worried Libya might fracture or slide deeper into anarchy, have been training Libyan armed forces and cajoling conflicting parties in government to work together, to little avail.
But diplomats say the nascent army would struggle in any case to take on Jathran's men, who helped overthrow Gaddafi. He defected last year as head of a state oil protection force, taking with him his armed men.