Muslims have been urged to turn away from the "harbingers of hate" following the terror attacks on London.
A "grassroots revolution" in mosques is being sought
The Ahmadiyya Muslim Association UK has called for a "grass roots revolution" in mosques to combat violent fanatics.
Group leaders expect 30,000 people to attend its annual convention in Aldershot, Hampshire, over the weekend, and want members to focus on peace.
The meeting is among a series of events being held across the country by Muslim organisations to debate terrorism.
'Root out fanaticism'
Ahmadi Muslims, who originally hailed from the northern India area of Punjab, believe that Mohammed was not the final prophet sent to guide mankind.
The majority of Muslims object to the community describing themselves as followers of Islam.
Rafiq Hayat, national president of the Ahmadiyya Muslim Association UK, called on members to honour the "true meaning of Islam - peace, tolerance, respect and service to humanity".
He said: "It's time for all Muslims to say enough is enough. We wish to practise Islam as exemplified by our founder Prophet Mohammad (peace be upon him).
"The word Islam means peace but we have to live by it in order to grow.
"We call for a grass roots revolution in mosques across the UK where ordinary people wish to make a future in the UK, for the sake of themselves and their children and for the sake of humanity, turn away from the harbingers of hate and root out fanaticism."
A group spokesman urged anyone who may be able to help police trace terrorist cells to follow "common sense" and tell what they know.
Elsewhere, thousands of families are attending the ongoing Living Islam festival in Lincolnshire.
The annual event is organised by the Islamic Society of Britain, an organisation which says it wants to strengthen the contribution of British Muslims to society.
Organiser Jeffrey Beere said this year's event had taken on a crucial additional meaning.
He said: "Islam is the faith of 1.6 million Britons. Its teachings fly in the face of the messages of hate that were behind the attacks on our capital.
"This is an opportunity in a million, a chance to live the universal values of compassion and care and to provide our youth with a positive, wholesome self-image."
Speakers include some of the most influential voices advocating a progressive application of Islam in the Western world.
Perpetrators of evil
Followers of the Salafi sect of Islam, a conservative or "pure" reading of the faith, are also organising lectures to speak against the attacks.
Some western analysts have associated Salafist thinking with al-Qaeda because some militant groups in the Middle East describe themselves by the same name.
But British followers of the sect say the association is completely wrong because they themselves have been targeted by militants for speaking out.
Scholars linked to Birmingham-based Salafi Publications will explain why they say Islam condemns suicide bombers as "perpetrators of evil".
A debate was held on Friday in Bradford and will be followed by others at mosques in Birmingham and London throughout August.