In Birmingham, Jama'at e Ahl e Sunnat, or the Sunni Council, said the bombings were against Islam, adding that any type of attack was against the Quran.
"Who has given anyone the right to kill others? It is a sin. Anyone who commits suicide will be sent to Hell," said Mufti Muhammad Gul Rehman Qadri, the council's chairman.
"What happened in London can be seen as a sacrilege. It is a sin to take your life or the life of others."
The council also targeted terror groups, who influence others to do their bidding, in the fatwa.
"Leaving aside the atrocities being committed in Palestine and Iraq, the attacks in London have no Islamic justification, are totally condemned and we equally condemn those who may have been behind the masterminding of these acts, those who incited these youths in order to further their own perverted ideology," the group's fatwa said.
Religious schools criticised
British Defence Secretary John Reid said religious schools in Pakistan were contributing to terrorism, amid reports that one of the alleged London bombers attended a so-called madrassa there.
In an interview with CNN's Late Edition, Reid said Pakistan President General Pervez Musharraf was an important ally in the war on terror and "has played a very constructive role in the aftermath of New York ... and the intervention in Afghanistan".
Religious schools in Pakistan are
accused of encouraging violence
But he expressed concern about religious schools in Pakistan.
"I think that people do recognise that the madrassas, literally schools in which terror is taught, are a major source of international instability and contribute largely toward the growth of terrorist activity," he told CNN.
"So we continue our discussions with President Musharraf."
The fatwa came as investigators in the northern city of Leeds - a focus of the investigation so far - continued searching a shop and a house near the home of one of the four alleged bombers, 22-year-old Shahzad Tanweer.
Pakistani intelligence agents have questioned students, teachers and administrators at the school in central Lahore, and at least two other radical Islamic centres, armed with pictures and a dossier on Tanweer.
One suspect had previously
been under police scrutiny
As the probe continued, The Sunday Times reported that another suspected attacker, 30-year-old Mohammad Sidique Khan, was scrutinised last year by MI5, Britain's domestic secret service, but was not regarded as a threat to national security or put under surveillance.
MI5 began evaluating Khan during an inquiry that focused on an alleged plot to explode a large truck bomb outside a target in London, thought to be a nightclub in Soho, the newspaper said. The private inquiry reportedly evaluated hundreds of potential suspects.
The Metropolitan Police declined to comment on the report, and a spokesman for Prime Minister Tony Blair's Downing Street office also refused to comment.
Asylum policy defended
The 7 July bombings, which killed 55 people on three underground trains and a double-decker bus, have prompted the government to propose new legislation outlawing "indirect incitement" of terrorism, including praising those who carry out attacks.
Charles Falconer, the Secretary for Constitutional Affairs and Lord Chancellor, on Sunday, rejected a suggestion that the government had previously been lax in its policies towards political refugees from Muslim countries and helped make Britain a fertile recruiting ground for Islamic terrorism.
"In terms of asylum, our policy is: If you are in fear of persecution, you are entitled to come here," the minister responded, speaking on the BBC.
"Obviously, if you then seek to attack the very state that you come to, that gives rise to different questions."
"But I don't think we have been ultra-liberal. What we have got to do now is unify all the forces in our society, in particular in the Muslim community, against those people who are fundamentally at odds with our values."