British police arrested a fifth person this afternoon after a fuel-filled jeep was rammed into Scotland's busiest airport in what police said was a terrorist attack linked to failed car bombings in London.
Police officers stand guard outside a house on Hatherley Street in Liverpool today after the arrest of a person in connection with Saturday's attack in Glasgow.
The mode, timing and targets of the attacks suggested a campaign linked to Prime Minister Gordon Brown's taking office earlier this week, security sources said. Mr Brown himself said he saw a direct link to radical Islamists.
"It is clear that we are dealing in general terms with people who are associated with al Qaeda," Mr Brown, a Scot who took office only last Wednesday, said in a sombre appraisal of the threat facing Britain.
Those arrested included a 26-year-old man and a 27-year-old woman seized on a major highway in northern England on Saturday night and another man (26) who was detained in Liverpool, 220 miles (355 km) south of Glasgow, today.
Two more men, described by witnesses as Asians, were taken into custody immediately after they slammed a Jeep Cherokee into Glasgow airport and set the vehicle ablaze yesterday.
Most of the Asian population in Britain come from the sub-continent, including India, Pakistan and Bangladesh.
Later today, police said they had carried out a controlled detonation of a suspicious vehicle left in the car park of a hospital near Glasgow where one of the two airport assailants was being treated for severe burns.
They said they believed the car was linked to the attack on the airport, but said it was not thought to contain explosives.
The airport attack, which caused five slight injuries and damaged the airport entrance, came barely 36 hours after two car bombs loaded with fuel, gas canisters and nails were found on the busy streets of central London primed to detonate.
Following the series of threats, Britain raised its national security level to "critical", meaning the risk of another attack was imminent, and increased security at airports.
"We are dealing with a long-term threat. It is not going to go away in the next few weeks or months," Mr Brown said.
Outside Glasgow, Scotland's biggest city, police in white body suits searched houses in a town a short drive from the airport and set up forensic tents behind one building.
Neighbours said two Asian men had moved into one of the houses a month ago but had kept very much to themselves. "I don't remember seeing them at all," said Mae Gordon (67). "They were the only people around here you would never see."
Britain has seen an increase in terrorism-related attacks since the September 11th strikes on the United States and since it joined US forces in invading Iraq in 2003. Some analysts believe the latest attacks may be designed to exert pressure on Britain to withdraw its troops from Iraq and Afghanistan.
Agencies