"Intensive contacts are being held with the Libyan authorities on how to deal with the hijack issue," the Sudanese Civil Aviation Authority announced in an urgent statement.

It said the plane, a Boeing 737, belonged to Sunair, a Khartoum-based private airline, and was carrying 87 passengers besides 8 crew members when it was hijacked.

The plane, which was on a routine flight between Niyala and Khartoum took off from the Niyala Airport in South Darfur State at17:30 local time (14:30 GMT) but was hijacked 30 minutes later.

The statement did not mention the number of the hijackers, nor the motives behind the action.

Meanwhile, a spokesman of the Sudan Liberation Movement (SLM)-Minawi Faction said three of their senior members were aboard the hijacked plane.

The SLM-Minawi Faction signed a peace agreement with the Sudanese government in 2006 while most of the other rebel groups refused the peace deal, demanding more compromises from the government.

The spokesman, Mohammed Bashir, said the three persons included an adviser of the former rebel group's leader Mini Arkou Minawi and one of the designers of the 2006 Darfur Peace Agreements.

Libya's Civil Aviation Authority confirmed the plane had landed at al-Kufrah, an oasis town in the country's southeast, Libya's state news agency Jana reported.

The Dubai-based Al Arabiya TV said the plane flew to al-kufrah to refuel and the hijacker wanted the plane to fly to Cairo.

The Egyptian state news agency MENA quoted Sunair as saying four men hijacked the plane. It said the Egyptian authorities have denied the permission for the plane's landing.