Tribal leaders and militia commanders have declared a semi-autonomous region in oil-rich eastern Libya.

Thousands of major tribal chiefs, militia heads and politicians made the declaration in a ceremony in the city of Benghazi.

Vowing to end decades of marginalisation under Muammar Gaddafi, the gathering named a council to run the affairs of the newly created region, extending from the central coastal city of Sirte to the Egyptian border in the east.

Libya's National Transitional Council, the interim central government, has repeatedly voiced its opposition to the creation of an eastern region, warning it could eventually lead to the break-up of the North African nation.

The gathering appointed Ahmed al-Zubair, Libya's longest serving political prisoner under Gaddafi, as leader of its governing council. Mr al-Zubair is also a member of the National Transitional Council.

He pledged to protect the rights of the region but also said his council recognises the NTC to run Libya's international affairs.

The gathering also rejected an election law which allocated 60 seats for the eastern region out of a 200-member assembly set to be elected in June.