A former altar boy has been jailed for 15 years for planting a home-made bomb on a busy Tube train .

Weapons-obsessed Damon Smith built the device at home with a £2 clock from Tesco after finding an online Al-Qaida article entitled "Make A Bomb In The Kitchen Of Your Mom".

Smith, 20, claimed it was a Halloween prank but was found guilty of possession of an explosive substance with intent following a trial at the Old Bailey .

The autistic defendant smiled in the dock as Judge Richard Marks QC sentenced him to 15 years in a young offenders' institution with an extended period of five years on licence.

Damon Smith

The judge said that although Smith, of Abbeyfield Road in Rotherhithe, had an interest in Islam, he was not motivated by terrorism.

But he told the defendant: "Quite what your motives were and what your true thinking was in acting as you did is difficult to discern with any degree of clarity or certainty.

"Whatever the position, the seriousness of what you did cannot be overstated, not least against the background of the fear in which we all live from the use of bombs here and around the world, an all too timely reminder of which were the events in Manchester earlier this week."

Smith, 20, has been jailed at the Old Bailey for 15 years for planting a home-made bomb on a busy Tube train

Speaking after the sentencing, commander Dean Haydon, head of the Metropolitan Police's Counter Terrorism Command, said: “We have seen this week the horrifying impact a bomb can have.

"And whilst there is no connection between Manchester and Greenwich it brings into stark reality just how devastating it could have been.

"The bomb Smith made was a viable device, but it failed to detonate, which was our good fortune.

“I would like to praise the public who informed the train driver of the abandoned bag; because of their quick intervention we were able to make it safe and identify Smith.

“At this time of heightened security we ask everyone to remain calm but alert, to report anything that causes concern immediately; if you have suspicions about someone's behaviour call police.”

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