Security stepped up at Norwich Airport

Security was stepped up at Norwich International today as Britain went on a full-scale terror alert.

Armed police are patrolling airports across the country after an attempt to crash a burning jeep into the terminal building at Glasgow Airport yesterday.

The failed attack was the third in 36 hours, following the discovery of two car bombs in Central London. Security services have raised the national terror threat level to critical - meaning an attack is expected imminently.

Police were mounting high visibility patrols at Norwich International and other regional airports.

Supt Julian Gregory of Norfolk police, said: “We have increased our policing presence at Norwich International Airport and we are working with our colleagues in the terminal to keep those arrangements in place for the time being.

“At this moment, the country is on a critical state of alert and we will be keeping a close eye on the situation. Our response will be in accordance with the national picture and depending on any intelligence we receive. We will continue to provide a high policing visibility across the county.

“Although there is no direct intelligence to suggest Norfolk could be at threat, we would ask people to be vigilant and report any suspicious activity to us.”

Bob Kent, Operations Director at Norwich International Airport, said passengers should check in as normal.

But he added: “Due to additional security measures on airport approaches, passengers are advised to allow extra time for their journey.”

Cars approaching the airport are being stopped and searched and extra officers have also been deployed on the streets of Norwich.

Prime Minister Gordon Brown today warned that the terror threat to Britain was “long-term and sustained”. He said Britain's message to the terrorists must be: "We will not yield, we will not be intimidated and we will not allow anyone to undermine our British way of life.'

Police are linking an attempt to ram a blazing Jeep Cherokee into the terminal building at Glasgow Airport yesterday afternoon with the discovery of two car bombs in London's West End on Friday.

All three vehicles were packed with gas canisters and nails, which could have killed hundreds had any of the bombs exploded.

Two men inside the Jeep were arrested at the airport, though one of them suffered severe burns after being engulfed in flames and is now in a critical condition in hospital.

Anti-terror officers from the Met and West Midlands Police later arrested a man and a woman, both in their 20s, in a car on the M6 motorway, in Cheshire. This afternoon Scotland Yard said another man had been arrested in Liverpool.

Police were today searching a number of houses near Glasgow Airport in connection with the attack there, Strathclyde Police said.

Mr Brown said the security services and public would have to remain “constantly vigilant” against the terror threat.

In his first broadcast interview since becoming Prime Minister on Wednesday, he said it was "clear' that the attacks in London and Glasgow were perpetrated by people who were associated with the global Islamist terror network al Qaida.

Speaking on BBC1's Sunday AM, Mr Brown said good progress had been made overnight in police inquiries, and enhanced security measures at airports and crowded public places, as well as increased checks on cars, can be expected.

British Transport Police said it was increasing patrols on the rail network and stepping up random searches on vehicles approaching stations.

People attending today's memorial concert for Diana, Princess of Wales, at Wembley Stadium are being warned to expect delays because of more thorough searches. Around 450 officers will be on duty to police the event.

Scotland Yard said police in London would be making greater use of their power to stop and search people under the Terrorism Act as a "visible deterrent and disruptive tactic'.