A group of American Muslims has started an online petition rejecting the use of terrorism.

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.

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.