(CBS/AP) A Jeep Cherokee trailing a cascade of flames rammed into Glasgow airport on Saturday, shattering glass doors just yards from passengers lined up at the check-in counters.
Police said they believed the attack was linked to two car bombs found in London the day before.
Britain raised its terror alert to "critical" - the highest possible level - and the Bush administration announced plans to increase security at airports and on mass transit.
One of the men in the car was in critical condition at a hospital with severe burns, while the other was in police custody, said Scottish Police Chief Constable Willie Rae. He said a "suspect device" was found on the man at the hospital and it was taken to a safe location where it was being investigated.
Rae would not say whether the device was a suicide belt. British security officials said evidence pointed toward the Glasgow attack being a suicide mission.
"I can confirm that we believe the incident at Glasgow airport is linked to the events in London yesterday," Rae said. "There are clearly similarities and we can confirm that this is being treated as a terrorist incident."
Police foiled the plot Friday after two cars were found in central London packed with explosives - one outside a nightclub near Piccadilly Circus and another parked nearby.
A British government security official said the methods used in the airport attack and Friday's thwarted plots were similar, with all three vehicles carrying large quantities of flammable liquid.
The official spoke on condition of anonymity because of the sensitivity of the information.
Police and MI5 had no intelligence warning of a plan to attack Scotland, but have monitored a host of suspected terrorists and plots there, he said. It was not yet clear whether there was an international element to the planning or funding of the attacks, the official said.
The new terror threat presents Prime Minister Gordon Brown, a Scot who took office on Wednesday, with an enormous challenge and comes at a time of already heightened vigilance one week before the anniversary of the July 7 London transit attacks, which killed 52 people.
"I know that the British people will stand together, united, resolute and strong," Brown said Saturday in a televised statement.
The green Jeep barreled toward Glasgow's main airport terminal shortly after 3 p.m., hitting security barriers before crashing into the glass doors, witnesses said.
Police subdued the driver and a passenger, both described by witnesses as South Asian - a term used to refer to people from Pakistan, Afghanistan and other countries in the region - arresting them and taking one to the hospital. Witnesses said one of the men was engulfed in flames and spoke "gibberish" as an official used a fire extinguisher to douse the fire.
Rae said a bystander was taken to the hospital with a leg injury.
The previous round of terrorist activity in Britain, in July 2005, was largely carried out by local Muslims, raising ethnic tensions in Britain.
"The car came speeding past," said Scott Leeson, a witness. "Then the driver swerved the car around so he could ram straight in to the door. He must have been trying to smash straight through."
Passengers fled running and screaming from the busy terminal, Margaret Hughes told the British Broadcasting Corp. "There was black smoke gushing out where the car had obviously been driven into the airport," she said.
The airport was evacuated and all flights suspended. Flames and black smoke rose from the Jeep outside the main entrance. It did not appear there were any injuries aside from the suspect who had been set afire. Police said Liverpool Airport and roads around Edinburgh were also closed.
The apparent attack left passengers shaken and stranded on the first day of summer vacation for Glasgow schools. All flights from the airport were suspended. At the time of the crash, the airport was bustling with families heading out on vacation.
Lynsey McBean, who was at the terminal, said one of the men took out a plastic gasoline canister and poured a liquid under the car. "He then set light to it," said McBean, 26, from Erskine, Scotland. She said the Jeep struck the front door of the airport but got jammed.
"They were obviously trying to get it further inside the airport as the wheels were spinning and smoke was coming from them," she said.
AP photographs from the scene showed the car hit the building at an angle and was poking into the terminal. The Jeep struck the building directly in front of check-in counters, where dozens of passengers were lined up, police said.
Leeson said bollards - security posts outside the entrance - stopped the driver from barreling into the bustling terminal at Glasgow's airport. "If he'd got through, he'd have killed hundreds, obviously," he said.
The incident carried reminders of a foiled plot in December 1999 to attack Los Angeles International Airport, when customs agents stopped an Algerian-born man in a car packed with 124 of explosives. He was jailed for 22 years and prosecutors said he was intent on bombing the Los Angeles airport on the eve of the millennium.
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