Britain's security alert raised to 'critical' following terror attack at Glasgow airport

Police in Glasgow said they have questioned the passenger of the crashed vehicle. The driver is under police guard in hospital.

Downing Street said that Prime Minister Gordon Brown is being kept fully informed on developments in the Glasgow inquiry and he has called Scotland's First Minister Alex Salmond to discuss the incident.

The government has now raised Britain's security alert to "critical" - the highest level possible - from "severe", which had been in place since last August.

The "critical" security alert is defined as "an attack is expected imminently".

The decision to increase Britain's level of security was made following the second meeting of the government's emergency crisis committee on Saturday.

White House spokesman Tony Snow said more local and federal security officers are being stationed at US airports in response to the incident at Glasgow airport and the car bombs found in London, but stressed there are no plans to increase the security level in the US.

The incident at Glasgow Airport occurred at 3:11pm on Saturday.

Witnesses said the attack involved two Asian-looking men driving a 4x4 vehicle at a dangerous speed. The vehicle reportedly crashed into the main doors of the terminal, though witnesses said the 4x4 was stopped by bollards just outside the terminal doors.

Taxi driver Ian Crosby was waiting outside the airport's Terminal One when the incident happened. He said the car "raced across the central reservation and went straight into the building."

A fire ensued in the vehicle. One of the two men was said to have run from the blaze with his clothing on fire. He was restrained by people outside the airport until police arrived. The man was sent to an area hospital for treatment of his burns.

Witnesses told how the second occupant of the vehicle struggled with police at the scene and was wrestled to the ground by officers.

Strathclyde police confirmed the two men were arrested. They are treating the matter as a terrorist attack, and Gordon Brown has this evening conducted an emergency security meeting.

The airport was immediately evacuated and all flights were cancelled.

Airports elsewhere in the U.K. stepped up security following the attack.

Police said one bystander was hurt in the incident. An unidentified man suffered a leg injury and required hospital treatment.

A police spokesperson said: "Strathclyde Police would like to reassure the public that it is unknown at present if this is connected with the incidents in London as inquiries are at an early stage.

"However, we would ask the public to remain vigilant and report any suspicious activity to the police."

Eyewitness Lynsey McBean, 26, from Erskine, Renfrewshire, said she saw the vehicle close to the main entrance of the airport. She said: "They were obviously trying to get it further inside the airport as the wheels were spinning and smoke was coming from them.

"One of the men, I think it was the driver, brought out a plastic canister and poured it under the car," McBean said. "He then set light to it. At that point, a policeman came over, the passenger got out of the car and and punched him.

"At that point I began to run away, but when I looked back, several people had run over to try and stop the men, who were Asian. I could see that one of the men was on fire."

Another eyewitness, Margaret Hughes, said people were screaming and running towards the terminal exit shortly after the incident.

She said: "As soon as I left the building there was black smoke gushing out where the car had obviously been driven into the airport."

She told how one of the men suspected of being behind the attack, who had himself been on fire, "seemed very composed" as he was led away by police.

Scott Leeson was at the airport awaiting the arrival of a colleague when the vehicle rammed into the terminal building.

He said: "The driver swerved the car around so he could ram straight into the door. He must have been trying to smash straight through.

"I spoke to an airport official who seemed to think that it was not an accident. He was very angry. He said the men in the car got out and started throwing petrol about - that must be how it caught fire."

Another witness described how he saw one of the men from the vehicle appear to throw a can of petrol over himself and the vehicle.

A spokesman for BAA, the operators of Glasgow Airport, said: "The vehicle caught fire on impact with the building and is currently outside the terminal building. A police investigation is under way and emergency crews are at the scene."

He said the airport had been closed as a result of the incident and a motorway cordon had been set up by the police.

Flights to and from the airport have been suspended until further notice, and passengers are advised not to attempt to travel to the airport. All incoming flights will be diverted to other airports.

Edinburgh International Airport remains open and flights are departing, but no vehicles are being allowed into the airport forecourt or near the terminal.

For more information, go to Glasgow Airport