One of the men suspected of the attack on Glasgow Airport worked as a doctor in Paisley, BBC Scotland understands.
One of the suspects is being treated at the Royal Alexandra
It is believed the man was employed as a locum doctor at the Royal Alexandra Hospital, just two miles from the airport building attacked on Saturday.
Greater Glasgow and Clyde Health Board said they could not comment because of the ongoing police inquiry.
Police have revealed that at least one of the five people arrested over the weekend was a qualified medical doctor.
It is understood that Home Office personnel were at the Royal Alexandra within 20 minutes of the explosion at Glasgow Airport.
Armed officers have also carried out raids on the hospital accommodation and a controlled explosion was carried out on a car parked at the hospital.
Police have also been searching houses in the Renfrewshire village of Houston, near Glasgow Airport.
None of the suspects involved in the Glasgow attack and the foiled London car bombings are British in origin.
The terror alert level was raised to critical - its highest level - after a Jeep Cherokee, loaded with gas cylinders, crashed into the doors of Glasgow Airport's main terminal and burst into flames on Saturday afternoon.
The attempted attack at the airport came a day after two Mercedes containing petrol, gas cylinders and nails were found outside a nightclub in London's Haymarket and in a nearby street. The devices failed to detonate.
Police are linking the failed bombings and the UK remains on high alert amid fears of a possible further attack.