The suspect was identified as Zabi ul Taifi, a Saudi national. He was among seven suspects caught in a Wednesday raid near the main northwest city of Peshawar - while US officials waited nearby, the Pakistani officials said.

Pockets of Pakistan's northwest region bordering Afghanistan are considered havens for al-Qaida and Taliban militants and potential hideouts for top al-Qaida leaders Osama bin Laden and Ayman al-Zawahri. The US has pushed Pakistan to go after the militants, while Pakistan has repeatedly requested that American officials share more intelligence to aid that effort.

The officials did not specify exactly what role Taifi is alleged to have played in the 2005 attacks in London, which were the deadliest on the British capital since World War II. However, the officials said that the "well planned" raid stemmed from a tip from American officials.

The officials said the Americans didn't participate in the raid, but were not far away from the militant hideout.

The suspects were in Pakistani custody and being questioned Thursday, said the officials, who requested anonymity because they were not authorized to speak to media.

"We have reasons to believe that we got the right man who had played a role in the 2005 attacks in London," said one official, who said he received the information from security agents in Peshawar.

The British embassy spokeswomen could not immediately be reached for comment Thursday, but Britain, which is home to many in the Pakistani diaspora, has long had concerns about terror activity in the South Asian country.

On a recent trip here, British Prime Minister Gordon Brown said three-fourths of the most serious terror plots investigated by British authorities had links to al-Qaida in Pakistan.

Suicide bombers of Pakistani origin were involved in the 2005 London bombings.

Presently, three other British Muslims - Waheed Ali, 25, Sadeer Saleem, 28, and Mohammed Shakil, 32 - are being retried on a charge of conspiring to cause explosions with the four bombers who blew themselves up aboard the three subway trains and bus on July 7 of that year.

2003 with Siddique Khan, the ringleader of the July 7 bomb plot. The three defendants being retried have pleaded not guilty.

The U.S. embassy spokesman could also not immediately be reached for comment Thursday. Pakistan's chief army spokesman, Maj. Gen. Athar Abbas declined to immediately confirm the Wednesday arrests.

One of the security officials said three other Arabs and three Afghans were also rounded up in the Bara Qadeem area.

Earlier, three intelligence officials and a police official also confirmed the raid and said the seven arrested men were suspected al-Qaida members. The officials requested anonymity because of the sensitive nature of the issue.