LONDON - THE tactic echoed the unthinkable cruelty of the Iraqi war zone.
The target was a crowded family restaurant. And the alleged attacker, who was wounded when his bomb went off prematurely in a restaurant bathroom, was a hulking 22-year-old who police say has mental problems.
Police in the England town of Exeter have charged Nicky Reilly, a British convert to Islam, with terrorism for the May 22 explosion.
They allege that extremists took advantage of his problems to groom him for a suicide mission.
'Our investigation so far indicates Reilly, who had a history of mental illness, had adopted the Islamic faith,' said Mr Tony Melville, a deputy chief constable of the Devon and Cornwall police force.
'We believe, despite his weak and vulnerable illness, he was preyed upon, radicalised and taken advantage of.'
Although the explosion did not get much international attention, it has raised concerns among Western anti-terror officials because it resembles cases in Iraq in which militants used people with mental problems for suicide bombings.
'It's a method that we are aware of in Iraq,' said a senior British anti-terror official.
'This shows we have to expand our attention to new areas where radicalisation can take place. Not just prisons or schools, but mental institutions and the mentally ill.'
The case and several other recent developments have put Britain on alert for attacks by lone-wolf militants and converts.
Every year since 2003, usually during the summer holiday season, extremists have tried to strike Britain.
They succeeded on July 7, 2005, when a group of Britons of Pakistani descent killed 52 people in suicide bombings on subway trains and a bus.
There have been several close calls, including a failed attack on Glasgow airport in July last year.
This year, the threat seems to have taken on a new face. Radicals have popped up in unexpected places with diverse backgrounds.
In April, police arrested a 19-year-old student from an affluent family in Bristol and confiscated explosives in his fortified top-floor apartment.
They began investigating Andrew Ibrahim after a tip from an imam whose suspicion was aroused when he noticed burn marks on the student's hands.
In Reilly's case, the suspect was a vulnerable, withdrawn youth from a troubled working-class home who developed mental problems in adolescence. He had converted to Islam, went to mosques and hung out with predominantly Kurdish and Turkish groups.
Anti-terror officials say such revelations are another sign that extremism in Britain has spread within an increasingly young and diverse population.
A study released last week found an increasing number of converts who have been swept up by violent radical ideology.
The most striking case in the study: a blond, non-Muslim immigrant boy in West Yorkshire who became obsessed with guns and violence and distributed Internet videos of militants beheading Westerners.
