By Jane Little BBC religious affairs correspondent

The Council on American Islamic Relations' petition, called "Not in my Name", follows the beheading in Iraq of a US hostage by a group said to be linked to Al Qaeda.

American Muslims have come under pressure to denounce extremism

The move reflects a growing defensiveness among American Muslims who feel they are being forced to prove their patriotism.

The message could not be clearer: "We hope this effort will demonstrate once and for all that Muslims in America and throughout the Islamic world reject violence committed in the name of Islam."

The tone, bordering on exasperation, betrays the deep sense of unease among American Muslims who have increasingly felt alienated by what they feel is a "with us or against us" mood that has deepened after the beheading of US hostage Nicholas Berg.

'Misperceptions'

Talk shows have revealed the pain and sometimes the ignorance of Americans who have associated the brutal execution with Islam.

And so the Council on American Islamic Relations has launched the petition and circulated a commentary in nationwide newspapers to correct what it calls the "misperceptions of Islam."

It quotes from the Koran to back its assertions that the killing of anyone in captivity is prohibited.

COUNCIL ON AMERICAN-ISLAMIC RELATIONS Based in Washington, DC Has 26 offices across US and Canada Reports a 70% rise in anti-Islamic acts in 2003 Says 300,000 signed petition in first few hours

And it says that just as America cannot be judged by what it calls "often misguided foreign policy" or torture committed by American soldiers, neither should the world of Islam "be held accountable for the un-Islamic and barbaric deeds of a minuscule minority."

The council this month reported a dramatic rise in anti-Muslim incidents in America.