(CNN) -- U.S. forces have handed possession of a tanker carrying an illegal oil shipment back to the Libyan government, the U.S. Embassy in Tripoli said Saturday.
The tanker, which had been seized by three armed Libyans earlier this month, had sailed last week from the rebel-held port of As-Sidra in eastern Libya. It was carrying oil owned by Libya's National Oil Company.
U.S. Navy SEALs boarded the Morning Glory last weekend in waters southeast of Cyprus at the request of authorities in that country and Libya. Saturday's handover also was carried out in international waters.
The transfer of the Morning Glory "went smoothly and as planned," the U.S. Embassy said.
Speaking on Libyan television, Libyan navy spokesman Col. Ayoub Qassim said three Libyan navy vessels had received the tanker early Saturday along with the three Libyan detainees, the crew and the illegal oil shipment.
They are bringing the Morning Glory back to the port of Zawiya, a city about 30 miles west of the capital, Tripoli, he said. The oil will be unloaded in the Zawiya refinery, but it's not clear who the detainees will be handed over to.
In a statement on Tuesday, rebel leader Ibrahim Jadran, who heads the federalist armed group that is holding key Libyan oil ports in the east and who attempted to sell this illegal oil shipment, denied the tanker was hijacked and accused the United States of "blatantly violating international maritime law" by boarding it.
He warned the United States against handing those on board over to the Tripoli authorities, saying they would get tortured and receive unfair trials. The government said they would be safe and treated according to Libyan and international law.
The situation remains unsettled in the North African nation, which the government is struggling to control more than two years after the ouster of longtime Libyan leader Moammar Gadhafi.
The conflict over oil wealth is stoking fears that Libya may slide deeper into chaos as the fragile government fails to rein in the armed brigades that helped remove Gadhafi in 2011 but now do as they please.
CNN's Ed Payne contributed to this report.