A bomb designed to cause “carnage” and planted on a London Underground train was made with materials sourced from Asda and Aldi a court has heard.

An Old Bailey jury heard commuters faced “a furnace engulfed in flames” when the device exploded at Parsons Green during London’s rush hour.

Iraqi asylum seeker Ahmed Hassan, 18, is accused of planting the bomb on the District Line on 15 September, 2017. He denies attempted murder and causing an explosion likely to endanger life.

The court heard that Mr Hassan originally told police he was responsible for the bomb.

One passenger, Aimee Colville, described “shards of glass flying through the air and then flames”. Jurors heard she could “smell herself burning and saw her hair was on fire”. Thirty people were injured in the incident: some badly burned, and others injured in the “stampede” as they fled in fear and panic, the Old Bailey was told.

Alison Morgan, prosecuting, told the jurors that Mr Hassan, packed a bomb with screwdrivers, knives and nails to cause “maximum carnage” on the rush hour Tube.

Jurors heard he bought metal items from Asda and Aldi supermarkets the day before the bombing. The court heard how Mr Hassan also researched the ingredients for TATP explosives and bought sulphuric acid on Amazon. To avoid suspicion, he allegedly used a friend’s address for the delivery of the largest component – hydrogen peroxide. The device, which was on a timer, partially exploded very shortly after the crowded train arrived at Parsons Green Station during rush hour.

Ms Morgan said: “There were approximately 93 people in the carriage when the device detonated. “The partial explosion created a large fireball. Some in the carriage were caught by the flames and sustained significant burns. “Many ran in fear and panic. They were fortunate. Had the device fully detonated, it is inevitable that serious injury and significant damage would have been caused within the carriage.”

The jury was shown CCTV pictures from inside the train showing a fireball engulfing the carriage as people ducked from the flames.

Passenger Jelena Semenjuk, noticed a bag on the floor and a man fitting the description of Hassan, the court heard. She heard a “loud bang” and her coat caught fire. She suffered burns to her legs, hands, and face, causing her eyebrows and lashes to be singed off.

Another passenger, Stephen Nash, noticed a “blinding light and the feeling that he was in a furnace engulfed in flames”, the court was told. The court heard that, after the explosion, hundreds of people in the station tried to get down a narrow staircase to get out.

Mr Hassan had got off the carriage at Putney Bridge Station before the bomb went off. He was arrested at the Port of Dover the next day.

Ms Morgan told the jury that when first arrested and questioned by police, Mr Hassan accepted that he was “responsible for the device” and told them there “may be a few milligrams traces” of explosives at his home address. She said the device was made from the volatile chemical explosive TATP and contained 2.2kg of sockets, screws, bolts, nails, knives and screwdrivers.

Jurors were told that Mr Hassan arrived in Britain in the back of a lorry via the Channel Tunnel in October 2015. He told authorities he was born in June 1999 in Iraq, but had no identity documents. He gave his name as Ahmed Hassan Mohammed Ali. Mr Hassan claimed asylum, and from 2016 lived with foster parents in Cavendish Road, Sunbury in Surrey. At the time he allegedly planned his attack his asylum claim was still outstanding, the court heard.

Jurors were told that on the day of the attack he left his home shortly before 7am and took the train from Sunbury to Wimbledon. In a toilet on the concourse, he set the timer on the device before boarding the District Line, four stops from Parsons Green.

Ms Morgan told jurors: “At any point, should he have wanted to, he could have stopped the timer. He could have pulled the wires out of the device. He could have stopped the detonation. “The CCTV footage from inside the carriage shows that at no stage did the defendant reach inside the bag to do anything.”

The court heard that after “calmly” walking away from Putney Bridge station, Mr Hassan boarded bus towards Earl’s Court where sat on the top deck at the front.

CCTV footage allegedly shows him glancing out of the window as he passes Parsons Green station. He is seen to remove the SD card from his mobile phone, chew on it and stuff it down the side of the bus seat, where it was later discovered by police in a destroyed state.

Mr Hassan bought a backpack and clothes and was seen on CCTV at Ashford, wearing a blue Chelsea football shirt, the court heard. He boarded a train and arrived in Dover at around 2.30pm BST where he is said to have bought a mobile phone and viewed the BBC News website which showed images of the scene he had left behind at Parsons Green.