The detectives allowed the alleged plot to continue for as long as they dared. They followed the young Muslim men’s movements in London and other parts of the UK, listened into their meetings and monitored their spending. But by late on Wednesday, with the suspected suicide bomb plans well advanced and an attack considered “imminent”, MI5 and anti-terrorist branch officers decided they could wait no longer without risking public safety.
During the night, 24 people were arrested in a co-ordinated series of raids on homes in London, High Wycombe and Birmingham.
By 2am, MI5, which is responsible for domestic security, had raised Britain’s threat level to the highest possible alert. Surprised airport staff were told to implement the most stringent security precautions, causing chaos at the airports.
John Reid, the home secretary, said security chiefs were confident that “we have the main players in custody” but the terror threat would remain at “critical”, which implies a terrorist attack is imminent, in case other members of the suspected terrorist cells were still at large.
Most of the people being questioned yesterday were believed to be young British Muslims, although police refused to rule out the possibility of international connections.
The Pakistan government said on Thursday night that the country’s intelligence helped to crack the plot and had arrested some suspects. A senior government official said “two or three local people” were held a few days ago in Lahore and Karachi.
In London officers were beginning the painstaking task of ascertaining the suspect’s true identities and nationalities, interviewing witnesses and searching homes and business premises.