NEW dramatic pictures today showed the deadly weapons left behind by Huddersfield suicide bomber Jermaine Lindsay and his gang.
The killers left a stash of 16 unexploded bombs as they set off on their deadly mission to London on July 7.
Chillingly, one was a nail bomb - designed to wreak maximum havoc if it went off.
Security experts believe the plot, which killed 56 people, may have been much larger and the explosives intended for a second strike.
Two theories emerged today after the publication of the photos:
* Did 19-year-old Lindsay and his accomplices mean to die?
* Or did they leave the stash for other bombers to use?
The bombs were recovered from a car believed to have been rented by suicide bomber Shehzad Tanweer, according to ABC News in the United States.
The vehicle was found days after the attacks in Luton, where the bombers boarded a train to London.
Exclusive pictures obtained by the US network show some of the bombs flat-packed like pancakes, while others were packed with nails to use as shrapnel.
An X-ray picture of one of the bombs shows nails bulging out of the side of a bottle-shaped bomb.
Security analyst Robert Ayers, told ABC: "Bombs don't kill by concussion. Small bombs, they kill by the blast effects of fragments of glass or metal, and this is designed to kill people."
He said he believed the explosives were left for a second strike.
The first pictures of the bloody wreckage deep in the London underground tunnels have also been obtained by ABC.
The extent of the devastation at Edgware Road station and on the train between King's Cross and Russell Square, where 27 were killed, was shown.
It was the train blown up by Lindsay, who grew up in Rawthorpe.
Mr Ayers said you could see how the bomb had blown out the train's sides and the roof had been blown to bits.
The photographs represent just the latest in a string of revelations about the London attacks made by the US media.
Most recently, a Joint Terrorist Analysis Centre report leaked to the New York Times revealed that three weeks before the attacks British intelligence officials concluded there was no group with the intent or capacity to attack the UK.
The leaking in America of the photographs could affect the relationship between British and US agencies, a leading congressman has warned.
Congressman Pete Hoekstra, chairman of the House Permanent Select Committee on Intelligence, expressed his concerns.
There is a widespread belief that US intelligence agencies, which are being kept updated by their UK counterparts, are behind the leaks.
Mr Hoekstra warned the USA's relationship with the UK could be damaged if further information emerged which Scotland Yard was trying to keep under wraps.
He said: "It's impossible to know how tight police are being with the details in London, but if the investigation is put in jeopardy, that would be a tragedy."
The nail bomb recovered from the car at Luton was "low end of the range", an expert said today.
Andy Oppenheimer, a weapons expert with Jane's Information Group, said: "These were not highly sophisticated devices. They were as nasty, squalid and revolting as any nail bombs used before.
"They may have been about to be deployed by other people. They also raise concerns about what other kinds of device might be out there."