U.K. raises security alert to 'critical' after Glasgow airport attack

Police arrested two men after their burning four-wheel-drive vehicle crashed against the entrance of the main terminal of Glasgow's international airport on Saturday afternoon.

Police arrested two menafter their burningfour-wheel-drive vehiclecrashedagainst the entrance of the main terminal of Glasgow's internationalairport on Saturday afternoon, sending passengers screaming from the scene and promptingauthorities to suspendflights.

Both men bailed out of the vehicle amid the broken glass and black smoke, witnesses said.

Two men in a burning Jeep crashed against the main terminal of Glasgow airport. ((Scottish Television via APTN/Associated Press) )

The men, including one whose clothes were engulfed in flames,scuffled with police andwerewrestled to the ground, according to bystanders. A maintenance worker at the airport said he believes the men deliberately set the vehicleon fire.

"This is being treated as a terrorist incident," Strathclyde PoliceChief Const. Willie Rae told reporters, describing the incident as "this horrendous criminal act."

He also said police believe it is linked to a failed attack Friday in London, when police seized two cars rigged as bombs before they could detonate.

"There are clearly similarities," he said.

Hours after the incident,Britain raised its security alert to "critical," the highest level possible and an indication that officials believe terror attacks are imminent.

Prime Minister Gordon Brown said: "It is right to raise the levels of security at airports and in crowded places in the light of the heightened threat."

Rae said one of the two men arrested in the incident is in critical condition in hospital. He said there was an explosive device "on his person"so the hospital was closed for a time while the device was removed.

He did not respond when a reporter asked ifthe itemwas a suicide belt. He also would not comment on the men, orprovide any information about them.

Flights suspended

Immediately after the crash,the airport — Scotland's largest — was evacuated and all flights suspended.Passengerswerekept away fromthe baggage collection area.

One of the two men arrested was engulfed in flames after the crash and is in critical condition in hospital. ((Scottish Television via APTN/Associated Press) )

Some passengers were left in planes parked on the tarmac, Rae said.

The green SUV barrelled toward the building shortly after 3 p.m., hitting security barriers before crashing into the glass doors and exploding, witnesses said.

One personwas hurt and hospitalized with a leg injury, Rae said.

Mercedes turned into bombs

The incident followsFriday's discovery of two fully intact car bombs in the heart of London. Authorities safely defused both devices plantedin two Mercedesparked not far from each other.

The first car was discovered parked near Piccadilly Circus; the second was found about an hour later, less than a kilometre away, near Trafalgar Square.

Government sources said the police and intelligence services were investigating a possible international link and similarities to car bombs used by insurgents in Iraq.

Late Saturday, British police arrested two people in Cheshire in northern England in connection with the events in London and Glasgow.

With files from the Associated Press