THIS is the moment an off-duty firefighter confronted one of the alleged July 21 bombers on the Tube.

Angus Campbell was travelling on the Northern Line when Ramzi Mohammed tried to detonate a rucksack bomb in front of him, it was alleged in court yesterday.

CCTV was shown in Woolwich Crown Court as Mr Campbell described the moment when the alleged Muslim fanatic tried to set off the bomb made from hydrogen peroxide, chapati flour, batteries and nails.There was about 20 or 30 people travelling in carriage between Stockwell and Oval when suddenly there was an explosion.

"I was sitting down, I was watching the woman opposite me. She had a small child, the small child was being quite lively, and she was trying to get it back into the buggy. I was mildly amused, I have small children and I often struggle with my children," Mr Campbell said.

Loud explosion

"I was sat there, and there was an explosion, it was loud. We were in a confined carriage and the explosion was loud. My first memory was being cowed.

"I remember my arm being over my head. I looked up through my arm - the first thing I remember seeing is Mr Mohammed, who was screaming and shouting, and there was smoke issuing from behind him, from his back and I think to the floor."

The firefighter of 21 years first went to the rescue of young mother Nadia Baro and her nine-month-old son.

Mrs Baro described how she saw a foam-like spongy substance leaking out of Mohammed's rucksack.

"I was in such a panic, I did not know how a bomb worked and I thought we were going to die now," she told the court.

Bits of nailShe said the substance coming from the rucksack had "bits of nails on it", and she could smell something "like the smell of oil".

After leading mother and child to safety, Mr Campbell returned to where Mohammed, from North Kensington, west London, was standing.

Dressed in shorts and a white T-shirt with "London" printed on the back, Mr Campbell yelled at Mr Mohammed.

"I was shouting 'What have you done, what have you done?' I thought at this point he was actually in pain," Mr Campbell said.

"I thought he was a victim and he was in pain."

He asked Mohammed what the sponge-like debris smoking on the train floor was.

'This is bread'

Mohammed muttered "This is wrong, this is wrong" and said innocently replied "this is bread".Mr Campbell said he approached and offered him help.

"I shouted 'you are scaring us, I want to help you, I can help you but I want you to lie down', because I wanted him to be submissive to me," he said.

"He became agitated and I would say aggressive."

Mr Campbell then pulled the emergency alarm lever and the train stopped at Oval station.

Mr Campbell said he shouted "don't open the doors" to the driver but seconds later the doors opened and Mr Mohammed ran off.

"He ran and he ran to his right. He went out of the door and he actually turned right and I remember him looking at me as he ran past me," Mr Campbell said.

"He ran past and as he ran he waved his hands, not a 'bye', more a fending off gesture."

Six accused

Mohammed, 25, is one of six men accused of attempting to carry out a series of suicide bombings on the London public transport system on July 21, 2005, two weeks after the July 7 bombings killed 52 people and injured hundreds more.

Also on trial are Muktar Said Ibrahim, 28, of Stoke Newington, north London; Manfo Kwaku Asiedu, 33, of no fixed address; Yassin Omar, 26, from New Southgate, north London; Hussain Osman, 28, of no fixed address; and Adel Yahya, 24, of High Road, Tottenham, north London.

Last week the jury saw dramatic CCTV footage showing the alleged bombers fleeing after their bombs apparently failed to detonate.

Photos of the defendants on an earlier camping trip in the Lake District were also shown as evidence.

However, all six deny charges of conspiracy to murder and conspiracy to cause explosions likely to endanger life.

The trial continues.