'Link between London attacks'
2005-07-22 18:21
London - Oozing rucksacks, harmless puffs of smoke, a foul smell and the failure of the latest apparent attempted suicide bombings in London suggest a link between this week's attacks and the July 7 atrocities, experts said on Friday.
Explosives specialists said the four bombs which apparently failed to explode on Underground trains and a bus on Thursday bore similarities to the type of al-Qaeda-style devices used in the July 7 suicide attacks, which killed 56 people.
Witnesses spoke of seeing a lard-like substance oozing from one of the would-be bombers' backpacks and smelling a strong vinegar-like odour after it failed to go off, suggesting the presence of an explosive mixture such as acetone peroxide, which was used on July 7.
That substance - made from sulphuric acid, hydrogen peroxide and acetone, which can be obtained from household products - deteriorates over time and becomes harmless if it is not used within days.
Speculated
Explosives expert Hans Michels, a professor at Imperial College in London, speculated that the July 7 and July 21 bombs came from the same batch.
"Everything suggests to me that this was from the same source, but that doesn't mean that the same terrorist group carried out the attacks. I think that the terrorists did not know the people who made it, and a middle-man distributed it to different groups.
"The first group did the job (on July 7) but the second group was just too late."
Chemist Andrea Sella, of University College London, agreed that the explosive probably came from the same source.
"If the bombers from July 7 and yesterday all loaded their rucksacks together two and a half weeks ago, then you might expect a substantial amount of the explosive to have disappeared by this week," she said.
Analyst
Abisha Moyo, a Zimbabwe-born business analyst who was on a train near Shepherd's Bush station when the incident happened Thursday lunchtime, described hearing a bang like a pistol shot and noticing a man lying on the floor with a rucksack on his back.
"He had his eyes shut and there was a puff of smoke coming from the bag," he was quoted as saying by the Daily Mail newspaper.
"The rucksack was ripped at the bottom, with some sort of muslin showing and some gooey lard coming out of it. I could see what looked like a pressurised canister or tube and there was a strong smell of vinegar," he said.
Detonators
Andy Oppenheimer, of Jane's Information Group, which analyses security and defence issues, said the detonators probably worked but the explosive was too degraded to ignite.
"It is an explosive that has to be used quickly after it is made. There is a possibility that that is what has happened here: rather than the detonators failing it is the actual explosive mixture that has failed," he said.
Media reports have said police have already found similarities between the explosives used in both attacks, but this has not been confirmed by the police themselves.