The official said the militia, called al-Awfea Brigade from the town of Tarhouna, 80 km (50 miles) southeast of Tripoli, demanded the release of one of their leaders whom they said had disappeared last night.

"The situation in the airport is very tense and tanks are surrounding the buildings. No one is allowed into the building," said the official, who declined to be named.

An airport customs official said flights were cancelled and incoming planes were diverted to Tripoli's Mitiga Airport.

The ruling National Transitional Council spokesman Mohammed al-Harizy said the Awfea head, Col. Abu Oegeila al-Hebeishi was kidnapped by unknown armed rebels while travelling between Tarhouna and Tripoli late last night.

(Reporting by Ali Shuaib; Writing by Hadeel Al-Shalchi; Editing by Angus MacSwan)

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