Muslim leaders have written to believers in London urging them to maintain UK security in the wake of this week's terrorism arrests.

The letter, distributed to mosque authorities across Britain, calls on clerics, or Imams, to instruct followers of their "obligation to maintain the peace and security of our country".

Iqbal Sacranie, author of the letter and general secretary of the Muslim Council of Britain (MCB), also asks the community to cooperate with police and other faith communities.

Eight men arrested on Tuesday morning in connection with a suspected terrorist plot against London remain in police custody at Paddington Green police station.

More than 700 officers from five forces across the capital and south-east England took part in the operation, codenamed "crevice", in which half a tonne of fertiliser - which could be used to build a bomb - was seized.

Criticism is levelled in the letter at the "sensationalised" reporting of the arrests, under headlines which do "immense damamge" to British Muslims and community relations, according to Mr Sacranie.

And there is a warning against against "hasty pronouncements of guilt" in the wake of the arrests.

The letter carries a reminder of the arrest in November 2002 of six young Muslim men, in connection with an alleged plot to release cyanide gas into London Underground.

Mr Sacranie writes that none of the six have been charged with any crime, "let alone being convicted of terrorist activity".

"There are other examples of incidents that have received prominent media attention only for the individuals to be subsequently released without any charges brought against them," he writes.

"The impact of such ordeals on the persons concerned and their families is unbearable."

London Mayor Ken Livingstone was quick to react to fears the terror swoop could lead to further alienation of the Muslim community.

After congratulating the Met on its work in foiling a terror attack, Mr Livingstone said London's communities stood "shoulder-to-shoulder" with their Islamic neighbours.

"All Londoners and all of London's communities have their part to play in the vigilance needed to foil the terrorists," he said.