Glasgow Airport has been closed and all flights suspended after a jeep which was on fire crashed into the main terminal building.
One man is reported to have been badly burned.
Eyewitnesses say a Cherokee jeep was driven at speed towards the building with flames coming out from underneath.
Later, Britain raised the security alert level to the highest rating of "critical".
The Home Office said that this is the highest level and indicates that an attack is expected imminently.
British Prime Minister Gordon Brown has urged people to be vigilant
Mr Brown said it was right to raise the security alert level to "critical" but said he believed the British people would "stand together, united, resolute and strong".
Police later confirmed that the crash was linked to the potential terrorist incidents in London's West End yesterday.
