UK terror threat now 'critical'

The UK's national terrorism threat level has been raised to "critical", Home Secretary Jacqui Smith has said.

The announcement came after a meeting of the government emergencies committee Cobra, following a burning car being driven into a Glasgow airport terminal.

Ministers, police and security service officials began their third meeting in three days at 1900 BST, this time with a video link to ministers in Scotland.

Cobra met earlier in the day to discuss the two car bombs found in London.

Police in the capital are checking CCTV footage in their investigation into the planting of two car bombs.

Strathclyde Police have arrested two people in connection with the incident at Glasgow Airport.

Eyewitnesses have described a Jeep Cherokee being driven at speed towards the main doors of Glasgow airport's terminal building with flames coming out from underneath shortly after 1500 BST.

The threat levels are:

*
critical - an attack is expected imminently
*
severe - an attack is highly likely
*
substantial - an attack is a strong possibility
*
moderate - an attack is possible but not likely
*
low - an attack is unlikely

Downing Street has refused to comment on whether the events in Scotland and London are connected, saying it was a matter for the police.

The BBC's Andy Tighe said there were "worrying similarities" between the two incidents but no-one in authority had yet made any "firm linkage."

Vigilance call

All flights to and from the airport have been suspended.

Both Mercedes were found to contain explosive materials

A Scottish government spokesperson said Scottish Ministers are in touch with their Whitehall opposite numbers and First Minister Alex Salmond and have spoken to prime minister Gordon Brown.

Mr Salmond and Justice Secretary Kenny MacAskill will be taking part in the Cobra meeting.

Scottish Conservative justice spokesman Bill Aitken said details about the incident were still "scant" but added: "Once the full information is available from Strathclyde Police we will need to react.

"I am sure that there will be a calm and realistic assessment and in the meantime one can only feel desperately sorry for the thousands of passengers who will have been inconvenienced as a result of what is clearly a serious incident."

Earlier in the day, Cobra met to discuss the London car bomb attempts.

Terror threat

In the early hours of Friday, two Mercedes containing petrol, gas cylinders and nails were found left outside the Tiger Tiger club in Haymarket and a nearby street but the devices did not detonate.

Unconfirmed reports suggest police may have an image of a suspect leaving the vehicle left outside the Tiger Tiger club.

Police increased patrols and security for events in London over the weekend, including the Gay Pride parade, the Concert for Diana at Wembley Stadium and the Wimbledon tennis championships.

raw fotage from airport

Police have urged anyone with information to phone the confidential Anti-Terrorist hotline number on 0800789321.