LONDON (Reuters) - Groups behind the July London bomb attack that killed 52 people and a failed attempt to strike again soon after appear to have been acting independently of an al Qaeda mastermind abroad, a newspaper reported on Saturday.
The Independent, quoting police and intelligence officials, said it was also likely that four July 7 suicide bombers were probably not linked to another group of four who failed to blow up explosives on buses and underground trains two weeks later.
But some of the report's conclusions were questioned by a terror analyst, who said it would be difficult for Islamic militants in Britain to prepare and set off explosive devices without some training in Pakistan, Afghanistan or elsewhere.
The newspaper said police and intelligence sources felt the fact there was no leader from abroad showed how other "self-sufficient" units could be hiding in Britain.
"All the talk about 'Mr Bigs' and al Qaeda masterminds looks like something from a film script at the moment," the newspaper quoted a police source as saying.
"Of course, things could change if new intelligence comes through, but it looks increasingly as if these people were largely working on their own. It is not something we expected."
Four young British Muslims blew themselves up on three London underground trains and a bus on July 7, killing 52 people. An apparent bid to repeat the attacks on July 21 failed and police have arrested four people they say were behind it.
The newspaper report quoted one counter-terrorist source as saying: "the key point is that the events were not connected. It appears they were self-contained, rather than being organised by some kind of mastermind."
The attacks have raised alarm in Britain that militants are living and operating in the country. Police have yet to establish whether they are acting alone or being directed by international networks like al Qaeda.
A police spokesman said they were investigating several lines of inquiry and would not comment on the details of the newspaper report. He would not rule them out either.
But a terrorism expert who did not want to be named said it took time and knowledge to prepare such attacks, and would not rule out the involvement of a foreign-trained mastermind putting the plots together either, possibly from inside Britain.
"They're crude devices, but I think there is a mistaken belief that you can just go on the Internet and download these things," he said.
"It was possible that they (the two groups of bombers) are not linked, but it's inconceivable that you could just spontaneously get a group of people together in two weeks, get the material, build the devices and carry out the attacks."
He said that "the old al Qaeda" had been "shattered" after U.S. military action in Afghanistan and the crackdown on militant groups in neighbouring Pakistan since 2001.
But that did not mean that people who lived and trained in those countries could not now be operating in Britain.
He said both sets of men suspected of being behind the attacks were not particularly well educated and described them as "misfits".
"People like that generally aren't capable of building bombs. There is definitely someone who has catalysed them, who has given advice on materials, provided technical expertise and maybe paid for all this," he said.
"I wouldn't rush to discount the idea that there is a mastermind or puppet master somewhere, it just may not fit the traditional description.
"The ringleader may be someone who lives in this country and spent sometime in somewhere like Pakistan or Afghanistan where they honed these skills."