A vulnerable Muslim convert was persuaded online by shadowy Pakistan-based extremists into trying to carry out a suicide bomb attack on a busy restaurant.

Nicky Reilly, 22, who has Asperger’s syndrome and a mental age of 10, was directed how to build bombs filled with hundreds of nails, which he attempted to detonate at the Giraffe restaurant in Exeter in May. The devices went off prematurely, injuring only him.

As Reilly admitted at the Old Bailey yesterday charges of attempted murder and preparing terrorist attacks, counter-terrorism officials said that extremists had taken advantage of his low IQ to groom him.

Reilly, who converted to Islam in his mid-teens, is thought to have encountered British-based Muslim radicals in internet cafés near his council home in Plymouth, which he shared with his mother.

Security sources said that radicals encouraged him to visit internet chat rooms and other websites where he encountered the men based in Pakistan who helped to mould a violent hatred of the West. Reilly, who appeared in court as Mohamad Abdulaziz Rashid Saeed Alim, set up his own page on YouTube, Chechen 233, where he discussed with the men who his targets should be. They answered his questions and directed him to bomb-making websites.

Reilly admitted yesterday researching how to make improvised explosive devices, investigating potential targets and acquiring components for them.

His mother insisted, however, that her son would never have been able to make the explosives himself. Kim Reilly said: “He would not be able to make the bomb. He would have had to have instruction or guidance from someone. I am absolutely convinced about that. There is no way Nicky was capable to do that.”

Officers said the failed attack was a terrifying echo of the tactics of extremists in Iraq who use the mentally or physically disabled to carry out attacks.

Neighbours said that Reilly was a recluse who spent most of his time online in his darkened bedroom. The influence of extremist websites and messages by jihadists is clear in a suicide note left at Reilly’s home.

In it he paid tribute to “Sheikh Osama” [bin Laden] and called on the British and United States governments to leave Muslim countries. He said Western states must withdraw their support of Israel and people would continue to use violence until “the wrongs have been righted”.

It was on May 22 that Reilly put his murderous plan into action. He left his home just before 11am with six glass soft drinks bottles in his rucksack. Three bottles were filled with paraffin and the others with caustic soda. When he arrived by bus at the Giraffe restaurant he ordered a drink from the bar and sat for ten minutes before heading to the lavatory to make the bombs.

Fortunately for the 24 customers and 11 staff in the restaurant and the other 20 people lunching outside, they exploded while he was in a cubicle. In his panic he could not open the door and suffered what his defence called “facial carnage”. He was arrested as he stumbled out.

Debbie Simpson, Assistant Chief Constable of Devon and Cornwall, said inquiries to trace his extremist contacts continued. Reilly, who appeared in court via a video link, was remanded in custody for sentencing next month.

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