Supporters of Shia cleric Muqtada al-Sadr take part in a rally in Baghdad on Saturday to denounce a draft U.S.-Iraqi security agreement. (Hadi Mizban/Associated Press)Supporters of a leading Shia cleric held a noisy rally in Baghdad on Saturday to protest a proposed U.S.-Iraq security deal that would allow U.S. troops to stay in the country beyond 2008.

A message from cleric Muqtada al-Sadr, reported to be in Iran, was read to tens of thousands of demonstrators after they marched from the eastern suburb of Sadr City to the central Mustansiriyah Square.

Al-Sadr said anyone who claims the agreement will end "the occupation of our land" or "tells you that it gives Iraqi sovereignty is a liar."

He also said the deal "will stigmatize Iraq and its government for years to come."

Protesters chanted anti-U.S. slogans and waved Iraqi flags during the march. At one point, they burned effigies of U.S. President George W. Bush and Secretary of State Condoleezza Rice.

Nasser al-Saadi, one of 30 parliamentarians loyal to al-Sadr, called for a referendum on the agreement.

The public show of opposition comes as U.S. and Iraqi leaders near a Dec. 31 deadline to reach agreement on the deal, which would provide a legal framework for U.S. troops to stay in Iraq after their United Nations mandate expires on Dec. 31.

The deal, which must be ratified by the Iraqi parliament, would allow U.S. forces to remain for another three years.

A copy of the draft accord obtained by the Associated Press specifies that U.S. troops must leave Iraqi cities by mid-2009 and be gone from the country by 2012.

Britain must also sign an agreement to enable its small contingent in southern Iraq to stay into 2009. London has said it will use the U.S.-Iraq deal as a blueprint for its accord.

5 killed in attack on U.S. allies

While al-Sadr's supporters protested, unidentified gunmen attacked the home of a U.S.-backed Sunni group north of Baghdad, killing five, the U.S. military said.

The masked gunmen attacked the home of a local leader of the Sons of Iraq, the name for the Sunnis who rejected al-Qaeda and backed the U.S.

The U.S. policy of encouraging Sunnis to reject the militants and back the Iraqi government has been successful in cutting violence, but has made the U.S. allies targets.

A pregnant woman was wounded in the attack, and was taken to hospital.

With files from the Associated Press