Al-Libbi remained silent for hours after his capture this week before finally confessing his identity to his interrogators, whose findings were passed on to American officials.

The two questions were being flung at al-Libbi in different shifts, said an official with inside knowledge of the interrogation.

Al-Libbi was arrested Monday after a gunbattle with security forces in northwestern Pakistan.

US President George W Bush hailed the capture as a victory that removes a key enemy and jubilant Pakistani officials said it would boost the hunt for Osama bin Laden.

The Libyan terror suspect, allegedly a close confidante of bin Laden, was Pakistan's most wanted man, accused of masterminding two 2003 assassination attempts against President Pervez Musharraf that left 17 people dead.

Two days after al-Libbi's arrest, security forces raided two homes in the northwestern tribal region of Bajor and arrested 11 terror suspects - three Uzbeks, an Afghan and seven Pakistanis.

Police also arrested six Pakistanis, including two women, and seized weapons after a raid Tuesday in an upscale residential area of Lahore.

But police officers denied reports that the arrests were linked to information provided by al-Libbi and said the Lahore operation appeared to be a family dispute. Another intelligence official said al-Libbi was being questioned by Pakistani counter-terrorism experts and security officials. He said Americans were not present at the interrogation but Pakistan shared its preliminary findings with the US.

Al-Libbi initially refused to speak, he said. ``He remained silent for hours, but he had to admit that he is al-Qaeda. He had no other option because our people had very solid evidence to prove his identity.''

Al-Libbi, who is thought to use at least five aliases, ranked below only Egyptian Ayman al-Zawahri and bin Laden in the terror group's hierarchy, US counter-terrorism officials claimed.

Commandos seized al-Libbi along with another foreigner - who has not been identified - after a firefight Monday outside the town of Mardan, near Peshawar.

Villagers in the Mardan suburb of Shahdand Baba said a small team of Pakistani security agency officers ambushed two people as they rode a motorbike across a graveyard. One was captured quickly, while the other - dressed in a burqa - escaped. He fled to the home of Mardan resident Zakir Khan and was pursued by Pakistani intelligence agents. The agents ``came in through our roof,'' Khan said.

``One man was hiding in the guest quarters and they found him there. He was a fat man with a long beard and a fair complexion.''

The arrest broke a long blank in the dragnet for bin Laden and his top lieutenants. The mastermind has evaded a manhunt since the September 11, 2001, attacks in the US. ASSOCIATED PRESS