"Those who cure you are going to kill you." That, says a British cleric, was the cryptic warning made to him by an alleged al-Qaida chief months before the failed bombings in Britain that have been linked to several foreign doctors working in the country. Many of the doctors were from the Middle East. Canon Andrew White, a senior British cleric working in Baghdad, said Wednesday that he met the man privately with a translator and a sheik after holding talks with Sunni Muslim tribal and religious leaders in the Jordanian capital of Amman on April 18. He meets regularly with extremists in an attempt to quell sectarian violence. He said religious leaders told him the man was an al-Qaida chief - an educated Iraqi in his 40s and dressed in Western clothes - who traveled from Syria to the meeting where he warned of attacks on Britain and the United States. "It was like meeting the devil," White told The Associated Press in a telephone interview from Baghdad. "He talked of destroying Britain and the United States and then said, 'those who cure you are going to kill you."' White, who runs Baghdad's only Anglican parish and has been involved in several hostage negotiations in Iraq, said he did not understand the threat's significance at the time. Although he said he passed the general threat warning on to Britain's Foreign Office, White said he did not mention the comment that seems to hint at the involvement of doctors. White said he gave the man's identity to the Foreign Office - a claim the government denies - but would not say publicly what it was. He also said he gave the same details to American authorities in Baghdad. All eight suspects who have been arrested in last week's failed car bombings in London and at Glasgow airport have been identified as medical workers or students. "As soon as I heard many of the suspects were doctors I remembered those words," he said. "I work with a lot of people who are not necessarily good people. It becomes very difficult to distinguish what threat is real and what is not." A spokesman for the Foreign Office who spoke on condition of anonymity in line with government policy confirmed White's meeting but said he did not identify the alleged al-Qaida chief. He also said White did not pass on the potential reference to medical practitioners and that because the information was vague it "didn't really merit further analysis." The information has since been passed on to the police in their investigation, the spokesman said. Prime Minister Gordon Brown, meanwhile, announced a crackdown on immigrants taking skilled jobs such as doctors. Recruitment practices of health service staff will be reviewed, and background checks will be expanded, he said. Questions were also raised over the government's knowledge of any of the eight suspects. Several of the men were on an MI5 watch list, a British government security official said, indicating that their identities had previously been logged by agents. One of the men on the list had posted a comment on an Internet chat room in condemnation of Danish cartoons portraying the Prophet Muhammad in a derogatory way, The Evening Standard reported, citing unidentified intelligence sources. It was unclear why the other suspects might have been put on the watch list. One suspect, Iraqi doctor Bilal Abdulla, reportedly had links to radical Islamic groups, and several others were linked to extremist radicals listed on the MI5 database, The Times of London reported. "Some, but not all, have turned up in a check of the databases, but they are not linked to any previous incident," the official said, speaking on condition of anonymity because of the sensitivity of the material. The official said Britain's security services are currently watching around 1,600 people and have details logged of hundreds more. Shiraz Maher, a former member of a radical Islamic group, said he knew Abdulla at Cambridge University. "He was certainly very angry about what was happening in Iraq...He supported the insurgency in Iraq. He actively cheered the deaths of British and American troops in Iraq," he told BBC television's "Newsnight." He said Abdulla berated a Muslim roommate for not being devout enough, showing him a beheading video and warning this could happen to him. He also said he had a number of videos of al-Qaida's former leader in Iraq, Abu Musab al-Zarqawi, who was killed by a US airstrike last year. Abdulla had been disciplined by his employers at the Royal Alexandra Hospital, outside Glasgow, for spending too much time on the Internet, according to the Evening Standard, suggesting the plotters might have planned the attacks in cyberspace. Some of the eight worked as colleagues at hospitals in England and Scotland. Experts and officials say the evidence points to the plot being hatched after they met in Britain, rather than overseas. Police seized several computers from hospitals in Glasgow, Stoke-on-Kent and Liverpool. While information held on the MI5 database did not alert authorities to the attacks, it did help police to round up suspects quickly, British media reported, quoting several unidentified government sources. Investigators believe the two men who left cars packed with explosives in London on Friday are likely the same two who drove a Jeep Cherokee into Glasgow Airport's main terminal a day later. Besides Abdulla, the other seven suspects include two doctors from India. Also in custody are a physician from Lebanon and a Jordanian doctor and his medical assistant wife. Another doctor and a medical student are thought to be from the Middle East, possibly Saudi Arabia. No one has yet been charged in the plot. The family of one suspect - Muhammad Haneef, a 27-year-old doctor from India arrested Monday in Brisbane, Australia - professed his innocence. Haneef worked in 2005 at Halton Hospital near Liverpool in northern England, hospital spokesman Mark Shone said. "He is innocent," Qurat-ul-ain, Haneef's mother, told the AP in the southern Indian city of Bangalore. Another suspect arrested in Liverpool was Sabeel Ahmed, a 26-year-old doctor, whose family in Bangalore, India, said Wednesday that he was related to Haneef but did not say how. "Both these boys are just caught in between," said his mother, Zakia Ahmed, a doctor, in front of her Bangalore home, which is in an upscale neighborhood about 12 kilometers (7.5 miles) from Haneef's home. She said Ahmed and Haneef had studied at the same medical school in Bangalore. She said she spoke to Ahmed briefly Tuesday and he was "keeping well." Investigators believe the main plotters have been rounded up, though others involved on the periphery, including at least one British-born suspect, were still being hunted, the British security official said.