British Home Secretary Jacqui Smith has insisted that the UK 'will not be intimidated' following the failed car bombings in London and Glasgow.
Addressing the House of Commons this afternoon, Ms Smith said that protective security measures had been stepped up and confirmed that this included greater use of stop and search powers.
Flanked by British Prime Minister Gordon Brown, she said 19 locations around the UK had been search by police as part of a 'fast moving investigation'.
Police have detained another man in connection with the failed car bomb attacks in Glasgow and London. Two suspects were arrested last night bringing the today number of people in custody to eight.
Police also have been given more time to question the three suspects being held in London.
None of those detained are of British origin and they include two doctors.
Information
Detectives say a great deal of evidence has been gleaned from the two unexploded car bombs found in London on Friday and the wreckage of the jeep that was driven though the front of the airport terminal at Glasgow on Saturday.
It also emerged today that police had information about the Glasgow attack before it occurred on Saturday.
Detectives had traced a house believed to be occupied by one of the Glasgow suspects after tracking phone records linked to the failed London car bomb attacks.
The letting agency responsible for the house had been contacted before the attack on the Glasgow terminal.
Police say they have established clear links between the London and Glasgow incidents and security has been tightened at airports and main railway stations across Britain.
Passengers have been warned to expect delays caused by the additional security measures.
At Heathrow, police checks and searches were in place from early this morning. All vehicles, including taxis, are being prevented from getting close to terminal buildings.
