Parsons Green attack: Teenage asylum seeker 'admitted bombing' after being caught by police in Dover

Suspect Ahmed Hassan wrote that he was 'bored, bored, bored' before attack

The alleged Parsons Green bomber confessed to making the explosives used in the attack when he was arrested by police while attempting to flee the country, a court has heard.

Ahmed Hassan scrawled that he was “bored, bored, bored” on his bedroom door before the terror attack, which failed when the device did not properly explode.

Experts told the Old Bailey the bomb left on a packed District Line train contained Isis’s signature explosive TATP (triacetone triperoxide), but failed to fully explode.

Explosives expert Sarah Wilson said just one gram of the highly sensitive substance could cause serious harm – and the device contained 400g.

“That has the potential to cause damage to property and harm or serious harm to those in closest proximity, which could potentially be lethal,” she told the jury on the third day of Mr Hassan’s trial.

“There would have been damage to the train, the infrastructure of the train, but also harm to those in closest proximity.”

Ms Wilson said there were a “number of reasons” that the bomb failed to explode, including faults in its manufacture or the explosive being too wet to fully detonate.

“It was likely to be a rapid burn rather than a detonation”, she added.

“The initiator mechanism, the battery, has functioned but the main charge had failed to function fully.”

But she confirmed that all elements necessary to make a viable bomb were present in the device, which incorporated a large amount of shrapnel piled in a bucket and concealed in a Lidl bag.

“You have the explosive, which is capable of exploding, but you then have a lot of small metal fragments which could also be expelled out some distance at that even,” Ms Wilson said.

CCTV footage showed 93 passengers on their way to work ducking for cover and fleeing when a fireball engulfed the carriage, with several burned and others injured in the crush to escape Parsons Green station.

Mr Hassan, an 18-year-old Iraqi asylum seeker, was shown on CCTV played to the court getting off the train one stop before the bomb exploded at around 8.20am after setting a timer on the device.

While changing his clothing several times, he journeyed via train to Dover, where he was stopped by police.

The Old Bailey heard that the teenager “shrugged” when caught, and then admitted making the bomb in an emergency interview carried out to assess ongoing risk to the public.

The device after it exploded on the District Line train at Parsons Green underground station on 15 September (Metropolitan Police)

Questioned about who created the device, Mr Hassan allegedly replied: “I did.”

On whether there were any more bombs, he added that there “may be a few milligrams, traces, at my home address”.

The media studies student had allegedly used a voucher awarded for being named “student of the year” to buy a key ingredient on Amazon and made it in the kitchen of his home in Sunbury while his foster parents were away on holiday.

Traces of TATP were found on the kitchen hob, sink and extractor fan, the court heard, as well as on a Tesco Clubcard in Mr Hassan’s name.

A box of nuts, bolts and screwdrivers was also seized along with three tubes of fake blood and a blue vase, jurors heard.

Officers searching the defendant’s bedroom discovered the word “bored” scrawled over back of his bedroom door over and over again.

A bottle of hydrogen peroxide he allegedly used to make the bomb was also found on his wardrobe and under his bed were stashed parts of a Maplin soldering kit, the Old Bailey heard.

Arabic nasheeds (songs) about battles and “clashing of swords” were also recovered.

A home-made video saved on a USB stick showed the destruction of a mobile phone in various different ways, including baking in the oven, battering with a child’s toy and flushing down the toilet.

The prosecution alleged the film, made for Mr Hassan’s media course, was “consistent” with his attempts to get rid of his mobile after the attack.

It was covered in ketchup, mustard and other liquids, wrapped in foil and baked in an oven, then taken into the back garden and hit with a hammer and an ornamental bird of prey, and run over by a child’s walker.

In the video, pieces of the handset are next put into a tumble dryer before being flushed down the toilet.

An Apple computer Mr Hassan was given to help with his studies was wiped the day before the attack, jurors have heard, and an SD card was found chewed up in a bus he boarded after leaving the Tube.

The court previously heard that the Iraqi asylum seeker told immigration authorities Isis trained him to kill after forcing him to become a child soldier shortly after arriving in the UK in the back of a lorry in 2015. But he denied being sent to the UK to carry out an attack on the terrorist group’s behalf.

Mr Hassan denies attempted murder and using the chemical compound TATP to cause an explosion that was likely to endanger life.

His trial will continue on Monday.

Additional reporting by PA