Describing the moment they thwarted two suicide bombers, including a suspected Indian engineer, intent on bringing death and destruction to Glasgow airport, two police officers have said the men were "resigned to death."

Police Constable Stewart Ferguson was off duty at the airport last Saturday and talking to Sergeant Torquil Campbell when they saw a blazing jeep wedged into the front of the building.

One of the occupants, believed to be the passenger -- Bilal Abdulla -- attacked Campbell. The officer said he was trying to keep him away from the burning vehicle.

As Campbell fought with him, Ferguson grabbed a fire extinguisher and hosed down the second man, suspected to be an Indian, Kafeel Ahmed. Ahmed is in a critical condition in hospital.

Ferguson, a 40-year-old father of two, told Sky News: "I remember his injuries, and to me they were the most horrific injuries I have seen on a living person. In my opinion, he was resigned to death."

Campbell, 49, said: "They were just waiting for death. The fact that they were still alive perplexed them a little bit and they didn't know what to do.

"It struck me when the second male came towards me on fire that this was something different, something out of the ordinary, and that this was indeed a terrorist attack. It was hard to comprehend, but I just had to accept the fact that terrorism had arrived at Glasgow airport."

Campbell, also father of two, who has almost 30 years' service, said that as he grappled with the first man, he saw the second appear out of the flames, on fire.

"I believe he had doused himself in petrol, but I never saw that," Ferguson said adding, "I thought 'What is in the vehicle?' because at that time I could hear popping and banging coming from the vehicle."

Ferguson said that when he saw Campbell being assaulted he thought that it was a road-rage incident.

"But it quickly dawned on me that this was no angry motorist - this was something completely different," Ferguson said.

As he looked at the jeep he saw the second man.

"He was well ablaze -- clothing, hair, skin -- and from the attitude that he was in, lying on his back, there was a kind of resignation about him. I was free to act, so, knowing where the fire extinguishers were in the building, I grabbed one," he said.

Restrictions at the airport were relaxed on Thursday.

Some taxis and buses were allowed back into the outer forecourt. All vehicles were searched before being allowed through. New arrangements were also put in place for disabled passengers.