LONDON - Police searched for evidence Thursday in a Scottish house that may have been used to produce the makeshift bombs that failed to explode in three attempted terror attacks on London and the Glasgow airport, officials and news reports said.

Community leaders in Scotland appealed for calm after Glasgow police said there had been dozens of racially motivated incidents since the attack on the city's airport Saturday.

At least two of the eight suspects caught so far rented a house a few miles from the airport where two men crashed a gas-laden Jeep Cherokee into barriers outside a terminal the day after two car bombs failed to explode in London, several British news outlets reported, citing unidentified sources.

The two men slept upstairs and used the downstairs as a bomb factory, the outlets said. Officials would not confirm or deny the reports.

Denis O'Donnell of the local Paisley Cab Company told The Associated Press that his taxis had picked up suspect Bilal Abdulla, an Iraqi-born physician, from the house nearly 20 times since May.

Neighbor Susan Hay told the AP that police said they were "stripping" the home Thursday morning to look for fingerprints and other forensic materials. A large tent -- set up on Sunday -- was hanging over the garage.

Two other suspects were arrested at staff housing at the Royal Alexandra Hospital in Paisley.

A British security official said authorities were still investigating whether there were any suspects at large who may have on the peripheries of the plot. The official requested anonymity because he was not authorized to talk to the press.

There have been 38 racist incidents in the Glasgow area since the attack, police said, including beatings and an attack on a white youth by three South Asian youths who believed he was involved in a previous racially motivated attack. A South Asian-owned shop was also set on fire in Glasgow, police said. There were no serious injuries.

Muslim community leader Bashir Maan appealed for calm and said community relations remained strong. "We must remember these people were not from Scotland," he said of the suspects held.

Also Thursday, a subway derailed in the capital during rush-hour, leaving at least 37 people with minor injuries in an incident transport authorities believe was caused by an obstruction on the tracks.

Britain's terrorism threat level has been lowered following the capture of the eight suspects, and a British investigator arrived in Australia to question a detained Indian doctor.

Australian police acting on information from British counterparts arrested Muhammad Haneef, 27, on Monday in the eastern city of Brisbane as he tried to board a flight with a one-way ticket.

Haneef worked in 2005 at a hospital in northern England where another suspect arrested in connection to the failed attacks also worked.

In a separate case, a man was convicted Thursday in Manchester of possessing terrorist training materials, including instructions on using gas canisters to make car bombs.

Prosecutors also said they found material on the computer of Omar Altimimi, 37, that identified nightclubs and airports as "suitable targets." He faces sentencing on Friday. However, police have reported no links between Altimimi, an asylum seeker who came to Britain from the Netherlands, and the recent foiled attacks.

Also Thursday, a group of al Qaeda inspired computer experts received prison sentences for running extremist Web sites. Prosecutors said the group gave advice, including on how to build suicide vests, to would-be terrorists from Web pages run from their London homes.

In the latest terror plots, six physicians are among the eight suspects, including the Iraqi Abdulla, one from Jordan, two from India and a man identified by Royal Alexandra Hospital staff as being from Lebanon. Also in custody are the Jordanian's wife, a medical assistant, and a doctor and medical student thought to be from the Middle East, possibly Saudi Arabia. None has been charged.

Relatives of the Jordanian and his wife have told their families they are "innocent," relatives said Thursday. Mohammed Jamil Asha, 26, and his wife, Marwa, 27, telephoned their families in Jordan separately on Wednesday, relatives said.

Indian Prime Minister Manmohan Singh offered his country's help in the investigations during a talk Wednesday with British Prime Minister Gordon Brown, said an official who requested anonymity because he was not authorized to speak to the media. Singh urged Brown to discourage the public from labeling all Indians abroad as terrorists, the official said.

Brown said there will be increased scrutiny of foreigners recruited for their skills, including doctors coming to work for the National Health Service.

"We'll expand the background checks that have been done where there are highly skilled migrant workers coming into this country," Brown told the House of Commons in his first appearance at the weekly prime minister's questions.

Several suspects were on a watch list compiled by the domestic intelligence agency MI5, the British security official said, indicating their identities previously had been logged by agents. The official did not say why they were put on the watch list. The official said Britain's security services are watching about 1,600 people and have details logged on hundreds more.

Two of the suspects -- 26-year-old doctor Sabeel Ahmed, whose family in India said he is related to Haneef, and Khalid Ahmed, 27, believed to be from Lebanon -- had applied for jobs in Western Australia state, said Geoff Dobb, state president of the Australian Medical Association.

He told the AP the pair had applied to work in the state health system since 2005 but were turned down because "they did not meet the standard required" but that "it had nothing to do with suspicions of any terrorist associations."