POLICE were still on high alert in London today, amid fears that a third terrorist cell could be plotting another strike in the capital.
Thousands of officers were on the streets and guarding Tube and overland rail stations as the huge security operation continued, despite all four suspected would-be bombers from July 21 being in custody.
Security sources have reportedly said that a third group, believed to be made up of British-born Muslims, was on the verge of attacking the Tube system last week.
The men are thought to be of Pakistani origin and have links with the Leeds-based terrorist cell which carried out the July 7 bombings which killed more than 50 people.
However, a Metropolitan Police spokeswoman said today that the possible existence of a third team of bombers was "media speculation".
She said: "We can't guarantee there won't be a third attack, but we have never talked of a third cell."