LONDON: A man who allegedly asked Twitter users for their thoughts on whether he should bomb a shopping centre or the London Underground went on trial in Britain on Tuesday.

Mohammed Rehman, 25, used the Twitter name 'Silent Bomber' with a profile picture of the militant known as "Jihadi John" and is said by prosecutors to have had a "keen interest" in the self-styled Islamic State (IS) group.

He was arrested in May this year after posting a tweet saying: "Westfield shopping centre or London underground? Any advice would be greatly appreciated."

That was accompanied by a link to an Al-Qaeda press release about the London bombings in 2005 which killed 52 people and four suicide bombers.

Rehman, 25, from Reading, west of London, is on trial at London's Old Bailey court accused of preparing terrorist acts and possessing an article for terrorist purposes. His wife Sana Ahmed Khan is also charged with preparing terrorist acts.

As Rehman was arrested, police also seized more than 10 kilograms of urea nitrate. The accused had allegedly tested explosives in his back garden.

"Given his prior knowledge, experience and the ready availability of the chemicals, the manufacture of a detonator would have taken no more than a couple of days and could have been done by him much quicker if he chose to," prosecutor Tony Badenoch told the court.

The pair deny any wrongdoing and the trial continues.

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