Authorities in Pakistan are looking into a connection between one of the London homicide bombers and two Al Qaeda-linked militant groups here, including a man arrested for a 2002 attack on a church near the U.S. Embassy, two senior intelligence officials said Friday.

The investigation is focusing on at least one trip that 22-year-old Shahzad Tanweer (search) made to Pakistan in the past year, said the officials, who work at two separate intelligence agencies and are involved in the investigation. They spoke to The Associated Press on condition of anonymity because of the secretive nature of their jobs.

One of the officials said that while in Pakistan, Tanweer is believed to have visited a radical religious school — or madrassah — run by the banned Sunni Muslim militant group Lashkar-e-Tayyaba (search).

"He only is believed to have spent four or five days there," he said.

In London, Metropolitan Police Commissioner Sir Ian Blair confirmed police believed they would discover an Al Qaeda connection to the July 7 blasts that killed 54 people, including the four bombers.

"What we expect to find at some stage is that there is a clear Al Qaeda link, a clear Al Qaeda approach, because the four men who are dead, who we believe are the bombers, are in the category of foot soldiers," Blair told British Broadcasting Corp. radio.

The sprawling school in Muridke (search), 20 miles north of the eastern city of Lahore, has a reputation for hostility. Journalists who have traveled to the school have been threatened and prevented from entering. Lashkar-e-Tayyaba was banned by Pakistani President Gen. Pervez Musharraf (search) for alleged links to a 2001 attack on India's parliament.

The official would not say when Tanweer is believed to have visited the school, but he disputed reports that he studied there. The short nature of the visit could indicate that Tanweer went there to meet someone or get instructions.

Tanweer's uncle, Bashir Ahmed, said from England that his nephew traveled to Lahore earlier this year to study Islam.

But the officials said they believed he also made a trip in the latter half of 2004, in which he met with Usama Nazir (search), a Pakistani militant arrested in November 2004 for helping plan a grenade attack on a church in Islamabad that killed five people, including two Americans, in March 2002.

Nazir, a member of the Al Qaeda-linked Sunni militant group Jaish-e-Mohammed (search), told authorities from jail Thursday that he met with Tanweer in Faisalabad, 75 miles southwest of Lahore, before his arrest.

It was not clear what the men discussed, or whether there was any connection between that meeting and the July 7 attacks against three trains and a double-decker bus.

Three of the four suicide bomb suspects — Tanweer, 18-year-old Hasib Hussain (search), and 30-year-old Mohammed Saddiq Khan (search) — were Britons of Pakistani ancestry. Reports say the fourth attacker was Jamaican-born Briton Lindsey Germaine (search).

The Times of London said investigators believe a Pakistani Briton in his 30s with possible links to Al Qaeda may have orchestrated the attacks. They believe he arrived in Britain last month and left just ahead of the bombings, the newspaper said.

It reported that the man, whom it did not identify, was thought to have chosen the targets.

Both Pakistani intelligence officials said the Interior Ministry has provided photos and profiles of the London bombers to intelligence agencies to help them determine whether they have any links to Al Qaeda suspects already in custody.

ABC News, citing unidentified officials, reported on Thursday that the attacks were connected to an Al Qaeda plot planned two years ago in Lahore.

Names on a computer that authorities seized last year from Muhammad Naeem Noor Khan (search), an alleged Pakistani computer expert for Al Qaeda, matched a suspected cell of young Britons of Pakistani origin, most of whom lived near Luton, where the alleged suicide bombers met up on their way to London shortly before the attacks, according to the report.

Authorities have now discovered ties between Mohammed Sidique Khan — one of the July 7 bombers — and members of that cell who were arrested last year, ABC said.

Pakistani intelligence officials reached by the AP would not immediately confirm that report, although they said information taken from Noor Khan's computer indicated plans for an attack in London, as was reported at the time of his arrest last year.

Interior Minister Aftab Khan Sherpao (search) said Wednesday that information provided by Pakistan helped thwart an attack timed for before Britain's general election in May. But London's police commissioner said he was unaware of any such plot.

Musharraf telephoned British Prime Minister Tony Blair and assured him of "Pakistan's fullest support and assistance" in the investigation into the London attacks, the state-run Associated Press of Pakistan news agency reported.

Blair thanked Pakistan for its "unequivocal support," APP said. It was not clear who initiated the call.