"A senior official of al-Qaeda in Yemen who was wanted by the police was arrested Wednesday night," in the Lawder area, one official told AFP.

Islamist sources named the man as Abdul Rauf Nassib, one of the most senior al-Qaeda officials in the Arabian peninsula republic, and the sole survivor of a missile attack launched from a US drone aircraft that killed six suspected al-Qaeda men in Maarib province of eastern Yemen on November 3, 2002.

Among the dead from the CIA-planned raid was Qaed Salem Sunian al-Harthi, suspected of organising a suicide bombing of the destroyer USS Cole in the southern port city of Aden that killed 17 American sailors in October 2000.

Security forces backed by helicopters, tanks and armoured vehicles were deployed Wednesday in Abyan where they surrounded a hideout of a large number of suspected Islamic extremists.

They were alerted after the Islamists, from Yemen, Algeria, Egypt and Saudi Arabia, had gathered in the Lawder/Jebel Thar region, 250km south of Saana and 150km northeast of Aden.

The fugitives were facing a 48-hour ultimatum that expires on Friday "to surrender unconditionally or face a military assault," according to the main Yemeni opposition party, Al-Islah.

The Islamist party's website (www.alsahwa-yemen.net ) said two men had surrendered overnight out of 150-200 people under siege at the hideout.