Two of the people being quizzed by police over the failed car bombings in London and Glasgow are believed to be doctors.
One of them is Dr Mohammed Asha, 26, of Newcastle-under-Lyme, Staffordshire, who was arrested on the M6 in Cheshire.
Dr Asha was arrested with a 27-year-old woman, believed to be his wife, and the two are being held at Paddington Green police station in London.
The second doctor held by police in connection with the car bomb attacks in Glasgow and London has been named as Iraqi national Bilal Abdulla by police sources.
He was seen wearing a stethoscope at his rented home in the village of Houston, near Glasgow Airport, letting agent Daniel Gardiner said. It is believed the doctor worked at Paisley's Royal Alexandra Hospital.
One of the two men is now under armed guard in a critical condition at the hospital after suffering terrible burns in the attack.
Police carried out a controlled explosion on a vehicle in the car park of the hospital. Strathclyde Police said the car was connected to the airport attack.
Dr Asha began practising in the UK in 2005 after qualifying in Jordan, according to the General Medical Council (GMC).
A spokeswoman said he held a type of provisional limited registration which enabled him to work in the NHS under supervision. The professional body would wait for the outcome of the police investigation before reviewing his registration, she added.
The access road to the Royal Alexandra Hospital was closed just before 3pm on Monday. A section of the main road outside the hospital was also shut off to traffic. The gathered media and pedestrians were ordered to move more than 200 yards away from the site.
