With helicopters overhead and snipers on rooftops, two convoys brought the men accused of the failed July 21 attacks to the Bow Street magistrates' court sitting at Belmarsh in south-east London.
Search teams checked cars entering the compound and armed officers stood guard outside the court.
The defendants Ibrahim Muktar Said, Yasin Hassan Omar, Ramzi Mohamed and Manfo Kwaku Asiedu were kept apart.
The men were led out for their first court appearance since their arrests more than a week ago, dressed in prison-issue navy blue sweatshirts or T-shirts and grey tracksuit bottoms.
The first to be brought before district judge Timothy Workman was Mr Said, 27, from Stoke Newington, London, who is alleged to have tried to blow up a bus in Hackney. Along with Mr Omar, 24, and Mr Mohamed, 23, he faces four charges: conspiracy to murder and attempted murder, both on 21 July, and conspiracy to endanger life by using explosives and making or possessing explosives with intent to endanger life.
But beyond the precise legal terms on the charge sheets, lawyers for the prosecution gave little detail of the investigation that transfixed Britain and culminated in raids by armed officers in London and Birmingham.
Second to appear was Mr Asiedu, 32, from Finsbury Park, north London, whose name was made public for the first time on Sunday by Scotland Yard. He is accused of conspiracy to murder and conspiracy to endanger life by making or using explosives charges which are understood to relate to the discovery of a rucksack bomb on open ground in west London.
Speaking through an interpreter using a Ghanaian dialect, Mr Asiedu told the court he had no fixed address. He then replied with a clear "yes" when asked whether he understood the charges against him.
Mr Mohamed, from North Kensington, west London, stood accused of trying to blow up a train at the Oval station.
Mr Omar, 24, from New Southgate, north London, was accused of trying to detonate a device at Warren Street station. He was arrested by police in Birmingham on 27 July. The hearing lasted 40 minutes six for each defendant and four in between. Each man was asked to confirm their date of birth and address.
As the allegations were read out, a fifth name was given on the list of claimed co-conspirators that of Hussain Osman, 27, who is being held in Rome ahead of extradition proceedings linking him to the failed attack on a train near Shepherd's Bush station.
Each of the defendants was then led away to a remand cell in the high security prison adjoining the court to await their next hearing at the Old Bailey on 14 November when their pleas to the charges will be formally entered. No applications were made for bail.
Three other men also appeared separately in the court on charges of helping the men accused of the July 21 attacks to evade arrest or failing to tell the authorities of their whereabouts.
Asias Girma, 20, from Stockwell, south London, is accused of failing to give information about Mr Osman and helping him to escape arrest while knowing he was a suspect. Wharbi Mohammed, 22, from Notting Hill, west London, appeared on the same charges relating to Mr Mohamed. Siraj Yassin Abdullah Ali, 30, from New Southgate, also faces the same charges relating to Mr Said and a separate charge of failing to disclose information about Mr Omar.
The three men were remanded in custody until 11 August when they will appear before Bow Street magistrates' court in central London.
* French intelligence produced a report shortly before the London bombings saying al-Qa'ida planned to attack Britain and would use the UK's Pakistani community to strike, Le Figaro reported. The DCRG, equivalent of the Special Branch, said in its 20-page report written in June that monitoring France's Pakistani community was vital if the country was to avoid violence.