A car on fire has been driven at the main terminal building at Glasgow Airport, police have confirmed.
Eyewitnesses have described a Jeep Cherokee being driven at speed towards the building with flames coming out from underneath.
They have also described seeing two Asian men, one of whom was on fire, who had been in the car.
Strathclyde Police said two people had been arrested and detained in connection with the incident.
The airport has been evacuated and all flights suspended following the incident at 1515 BST.
A Whitehall spokesman said the incident was not being treated as a national security threat however the prime minister is being kept informed of developments and is expected to chair a meeting of COBRA - the emergency committee later.
They might be saying it's not a national security threat, but it follows after Friday's car bomb threats in London. :(
Update
Actually, the government reconsidered. From the BBC:
Home Secretary Jacqui Smith said the national terrorism threat level had been raised to its highest level of "critical", meaning an attack was expected "imminently".