"All acts of terrorism targetting civilians are â€˜haramâ€™ (forbidden) in Islam," the fatwa or religious edict issued by the FiÃ h Council of North America (FCNA), a group of scholars that interprets Islamic law, said.
The edict, signed by 18 Islamic scholars who serve on the FCNA, is endorsed by over 100 Muslim organisations, mosques and leaders.
"There is no justification in Islam for extremism or terrorism," said the fatwa, issued here in English, Arabic and Urdu.
"It is 'haram' for a Muslim to cooperate with any individual or group that is involved in any act of terrorism or violence," it said, adding "it is the civic and religious duty of Muslims to cooperate with law enforcement authorities to protect the lives of all civilians."
The scholars said the fatwa is in response to the blasts this month in London and Egypt, and that they wanted the message to reach both non-Muslims who believe that Islam supports terrorism, as well as Muslims in North America and elsewhere, especially youths who could be susceptible to Islamic extremism.
"Suicide bombing is forbidden in Islam," said FCNA president Muzammil H Siddiqi.
"Tragetting civilians' life and property through suicide bombing or any other method of attack is 'haram'," the fatwa said.