The man detained over a suspected suicide bomb attack in Exeter was an autistic 22-year-old allegedly radicalised by a gang of suspected Muslim radicals who were being monitored by police and MI5, The Daily Telegraph can disclose.

Investigating officers said that Nicky Reilly received a text message of "encouragement" hours before the nailbomb attack in a family restaurant.

Police have made the first arrests as the net closed in on the suspected radicals alleged to have groomed the bomber.

Sources close to the investigation said that the alleged corruption of a vulnerable young man - who suffered from Asperger's Syndrome, had a history of self harm and had attempted suicide several times - was a "new horrific low" for Muslim extremism in Britain.

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Detectives believe Mr Reilly planned to commit suicide and allegedly had help in constructing three "rudimentary but viable" bombs that had never been seen in Britain before. They were constructed from sodium hydroxide, aluminium foil strips and an essential oil, combined with kerosene.

It was confirmed that there were three devices in a bag packed with nails. One was partially detonated in the toilets of a restaurant in the Princesshay centre. The other two failed to go off.

"It could be set off by shaking the mixture but we are still not sure if the device was being primed or it was actually planned to be set it off in the toilets, in the belief it would blow out the whole restaurant" the source added.

Full article here.