Nine men were remanded in custody on Monday charged with plotting to cause explosions in Britain and other terror offences, a week after they were arrested in pre-dawn raids.
The men appeared at City of Westminster Magistrates Court on charges of conspiracy to cause explosions "of a nature likely to endanger life or cause serious injury to property" between October 1 and November 20 this year.
The suspects, aged between 19 and 28, also face charges of involvement in the preparation of an attack by having downloaded and researched methods and materials, and of scouting potential targets.
At least five of the men are of Bangladeshi origin.
A dozen suspects were arrested but three were subsequently released.
Sue Hemming, of Britain's prosecution service, said before the hearings that sufficient evidence had been uncovered to bring charge of "conspiracy to cause explosions" and preparing "acts of terrorism" with the intention of either committing the acts themselves or helping others to do so.
Hemming said prosecutors had decided to file the charges against the nine men after reviewing evidence provided by the West Midlands counter-terrorism unit.
Lord Alex Carlile, Britain's independent reviewer of counter-terrorism laws, told lawmakers at the time of the arrests that the allegations against the men involved a "significant" plot.
A bombing in the Swedish capital Stockholm earlier this month has heightened concerns in Britain because the man thought to have been the attacker lived in the town of Luton near London.
Swedish investigators say they are "98 percent certain" that the man who blew up his car and himself was Iraqi-born Taimour Abdulwahab.
He had attended a university in Luton and had been living for the past few years in the town with his wife and three children.
Representatives of the mosque he attended have spoken of a popular man who developed extremist views.
It is believed Umar Farouk Abdulmutallab, the Nigerian being held in the United States on charges of trying to bomb a Detroit-bound passenger jet with explosives in his underwear a year ago, was radicalised while a student in London.
Five years after four suicide bombers killed 52 innocent people on London's transport network, Britain is on high alert after having upgraded its perceived terror threat level earlier this year to "severe."
This is the second highest on a five-level grading, indicating that a terrorist attack is "highly likely," according to the Home Office, Britain's interior ministry.
The threat level was hiked in January after a six-month spell at "substantial" -- the only time it has dipped below the two highest levels since it was set up in 2006, following the London bombings in July 2005.
The suicide bombers who unleashed their explosives on three Underground trains and a bus were all British nationals.
Source: AFP Global Edition