Fourteen people have been charged over the alleged plot

Mohammed Shamin Uddin, 35, Mohammed Yasar Gulzar, 25, and Nabeel Hussain, 22, are accused of conspiracy to murder and preparing an act of terrorism.

The men, all from London, were remanded in custody by City of Westminster magistrates until 18 September, when they will appear at the Old Bailey.

Eight other men have already been remanded on the same charges.

A further three people have been charged with failing to disclose information.

Officers have until Wednesday to question five other people still being held, after which time they must charge or release them or apply for more time to question them.

Detention deadline

All the suspects were arrested in raids in London, Birmingham and High Wycombe, Buckinghamshire.

Mr Uddin, from Stoke Newington, north London, Mr Gulzar, from Barking, east London, and Mr Hussain, from Chingford, east London, are accused of conspiring between 1 January and 10 August 2006 to murder other persons.

They are also charged with planning to intend "to smuggle the component parts of improvised explosive devices onto aircraft and assemble and detonate them on board" contrary to section 5 (1) of the Terrorism Act 2006.

Mr Hussain's brothers, Mehran and Umair, are among the three people facing less serious charges.