Spotting would-be terrorists in the classroom is not the job of teachers, the head of schools in Leeds has said. Three of the four London bombers hailed from the city, and one was a learning mentor at a primary school.

Chris Edwards, the chief executive of Education Leeds, the council-owned company which runs the city’s 277 schools, said: “How can we stop this happening again? We can’t. It is not at the heart of what we do.”

Mohammad Sidique Khan, 30, who killed seven people in the Edgware Road bomb, was a learning mentor at Hillside primary school up until December 2004. He grew up in Beeston and was a pupil at Matthew Murray school.

Hasib Hussain, 18, blew up the Number 30 bus in Tavistock Square, killing himself and 12 others. He left Matthew Murray (now South Leeds high) with seven GCSE passes in 2003. Shehzad Tanweer, 22, from Colwyn Road in Beeston, studied sports science at Leeds Metropolitan university. He killed seven people in the Aldgate tube bomb.

Mr Edwards said that Leeds already had a range of anti-racism policies that would combat any extremist views aired in schools. “This is not the fault of the education system. This is not about disaffection. These were successful men. One had good qualifications, another was a hard-working learning mentor. That is why it is so hard to come to terms with.”

But Jamil Ahmed, the general secretary of the Leeds Islamic Centre and manager of the city’s Harehills education action zone, said: “Parents, schools, and community leaders need to work together to make young people feel comfortable about questioning established values, to prevent them from being hijacked by outside, extreme influences.

“They have to feel that they can talk openly about their concerns.”

Colin Bell, head of South Leeds high school, said: “We have robust anti-racist policies in place.

“Any anti-western sentiments would be treated as racism and not tolerated.

“I looked through Hasib Hussain’s school records and he had about two detentions in five years. That is pretty normal for a teenage boy.”

Apart from lessons stopping for the two-minute silence last Thursday and around six children receiving counselling, it has been business as usual at the 1,300-pupil school: “The staff want to move on. Like the rest of us they wish it had never happened,” said Mr Bell.

Staff at Hillside primary, Beeston, where Khan worked as a learning mentor, have received counselling from Mike Haworth, a senior educational psychologist with Education Leeds.

“The teachers are reassuring the children that everything is going to be OK. The staff have expressed guilt about not having picked up what was going on. I have told them if MI5 can’t pick it up, they are not going to.”

Sarwar Khan, secretary of the Kashmir Muslims’ Welfare Association, said that Khan was well known and liked in Beeston and respected for the work he did with young people: “Nobody here was aware of Sidique’s dark side. We are still feeling the shock.

“We have worked hard to build up community relations, to improve the health and education of Muslims in Beeston, and what has happened will set us back 20 or 30 years.

“This terrible act has made a very big dent in our efforts.”