BAGHDAD, Dec 25 (Reuters) - U.S. forces shot and killed a Sunni Muslim cleric during a raid on his Baghdad home, an influential group of Iraqi clerics said on Saturday and warned that the incident will fuel anger against the United States.

But the U.S. military said it was unaware of the incident.

The Muslim Clerics' Association said the killing on Friday of Sheikh Mowaffak al-Douri, preacher of Baghdad's Abi Bakr al-Siddiq Mosque and a member of the group, was the latest in a series of attacks on Iraqi mosques and clerics.

"They raided his house and executed him with all brutality and criminality, as well as repeatedly targeting mosques and houses of worship," it said in a statement.

"This will deepen feelings among Iraqis that the war being waged against them for over a year and a half is a religious, racist war, not a war on terrorism...and will help foster terrorism and spread it throughout the world."

Iraqi forces, backed by U.S. troops, regularly raid mosques and have arrested Sunni clerics they say are linked to insurgents bent on expelling foreign forces from the country.

The Muslim Clerics' Association, which has called on Iraqis to boycott the Jan. 30 elections in protest over last month's U.S.-led offensive on the Sunni city of Falluja, says its members have been specifically targeted as part of a campaign to silence dissent.

The Association, which has thousands of members across the country, helped negotiate an end to a previous assault on Falluja in April and has helped win the release of foreigners kidnapped in the country.