LONDON — London commuters have testified that they were left with singed hair and burns after a fireball tore through a subway carriage last year.

Teenage Iraqi asylum-seeker Ahmed Hassan is accused of planting a bomb on the London Underground train on Sept. 15. It partially detonated, injuring 30 people.

Prosecutors say the bomb contained shrapnel and 400 grams (almost a pound) of explosives inside a plastic bucket wrapped in a shopping bag. They say Hassan left it on the crowded train, getting off one stop before it exploded.

Commuter Stephen Nash told jurors Thursday at London’s Central Criminal Court that he was reading a newspaper when there was a blinding flash and he was “engulfed in flames.”

Hassan denies attempted murder and using the chemical compound TATP to cause an explosion.