A man suspected of being al Qaida's chief operative in the UK lived in the same flat as the Brighton bomber.

Armed anti-terrorist officers who swooped on the London flat of Abu al-Hindi were raiding the same property used by IRA bomber Patrick McGee, who carried out the attack on the Grand hotel 20 years ago.

Codenamed Bilal, al-Hindi is thought to have been under surveillance for weeks and was the main target of last Tuesday's operation.

He and four other men were arrested at the address in Willesden, north London.

Last night he was among nine men aged between 19 and 32 being questioned by police at Paddington Green police station. They are being detained on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism.

Officers now have until tomorrow to interview the men.

Landlord Michael O'Sullivan, who has owned the property since 1983, said: "It's bizarre because after the Brighton bomb in 1984, officers raided the same flats."

Al-Hindi is suspected of carrying out surveillance at potential US targets, is the author of a guerrilla training manual and worshipped at Abu Hamza's Finsbury Park mosque.