GLASGOW, Scotland — The suspects who parked explosive-laden cars in London are believed to be the same two suspects who rammed a Jeep Cherokee into Glasgow airport last Saturday, British officials said Tuesday.
It was the latest theory in the quick-moving investigation, in which police have turned their focus to a growing number of physicians with roots outside Britain — including a doctor seized at an Australian airport.
Meanwhile, Britain on Wednesday cut its national securityrating to "severe" from its highest level "critical," saying the threat of a terrorist attack was no longerimminent.
A "severe" rating means an attack is "highly likely."
A British government security official said investigators were looking into the connection between the drivers of the vehicles in London and in Scotland, and NBC News confirmed that authorities, speaking on condition of anonymity, believed the same two men were behind both attacks.
Also Tuesday, a senior U.S. counterterrorism official told NBC News' Robert Windrem that British authorities suspect and are investigating a connection between the doctors involved in the London and Glasgow attacks and al-Qaida in Iraq.
"The concern is serious," the official said. "There are suspicious contacts, but they haven't yet put flesh on the bones."
The official hinted strongly that British attention is focused on Bilal Abdullah, the Iraqi diabetes doctor who was educated at the University of Baghdad and came to the U.K. in 2004. He worked in a hospital in Iraq, according to reports.
Senior U.S. intelligence officials told Windrem that British authorities now believe "the key of the key suspects" in the terrorist plot have now all been detained. The official stopped short of ruling our further arrests.
One official said the investigation moved quickly because the suspects did not cover their tracks. "These guys left behind a gold mine of evidence," the official said.
Police said at least four suspects had worked as doctors in Britain: two from India, one from Iraq, one from Jordan.
Staff at a hospital near Glasgow on Tuesday identified a fifth suspect — the man badly burned Saturday after trying to ram a Jeep loaded with gasoline canisters into the airport Saturday — as Khalid Ahmed, a Lebanese doctor on staff there.
The investigation into attempts to set off two car bombs Friday in London and to ram the Jeep loaded with gasoline into the Glasgow airport was expanding overseas and into Britain's medical community.
Arrested in Australia
One of the suspects from India, 27-year-old Muhammad Haneef, was arrested late Monday at the international airport in Brisbane, Australia, where he was trying to board a flight with a one-way ticket, the Australian attorney general said.
Haneef worked in 2005 as a temporary doctor at Halton Hospital in England, hospital spokesman Mark Shone said. Australian officials said he studied medicine in India before working in Liverpool, England, and then going to Australia.
Another suspect, a 26-year-old arrested Saturday in Liverpool, also practiced at Halton Hospital as well as at nearby Warrington Hospital, Shone said. He refused to identify him.
Police said two other men, ages 25 and 28, were arrested Sunday in residences at the Royal Alexandra Hospital near Glasgow. Staff identified them as a junior doctor and a medical student.
None of the suspects named so far are on U.S. terror watch lists that identify potential suspects, according to a senior U.S. counterterror official who spoke on condition of anonymity because of the sensitivity of the issue.
Pakistan and several other nations have been asked to check possible links with the suspects, a British security official said. British-born terrorists behind the 2005 London transit bombings and other thwarted bomb plots have had ties to terror training camps and foreign radicals in Pakistan.
'No specific information'
Amid increased security at British airports, train stations and on city streets, two men attempting to buy gasoline canisters at an industrial estate were arrested in Blackburn, northern England, under anti-terrorism laws.
Cameron Mason, managing director of Barcode Logistics, a local business, said the men had arrived to collect about eight large gasoline canisters left outside a building.
British officials said it was too early to say if the men were linked to the London and Glasgow attacks.
In Glasgow, a bomb disposal team carried out a controlled explosion on a suspicious car parked outside a mosque early Tuesday, calling it a precaution.
And part of London's Heathrow Airport Terminal 4 was closed while officials checked a suspicious package Tuesday, police said. The terminal later reopened.
The other suspects identified by police:
- Bilal Talal Abdul Samad Abdulla, 27, from Iraq. According to the British General Medical Council's register, a man named Bilal Talal Abdul Samad Abdulla was registered in 2004 and trained in Baghdad. Staff at Royal Alexandra Hospital near Glasgow said Abdulla was a diabetes specialist there.
- Mohammed Jamil Abdelqader Asha, 26. A Jordanian official said Asha was of Palestinian descent and carried a Jordanian passport.
"I didn't even have the impression that he was religious," said Azmi Mahafzah, Asha's instructor at the University of Jordan medical school. "He is not a fanatic type of person."
- Marwa Asha, his wife, identified in news reports as a medical assistant. Her family denied she was a militant.
"Marwa is a very educated person and she read many British novels to know England better, a country she liked so much," her father, Yunis Da'na, told The Associated Press in Jordan.
NBC News and The Associated Press contributed to this report.