Protesters march through Sadr City

BAGHDAD, May 26 (UPI) -- Thousands of members of the Mehdi Army marched through the Sadr City section of Baghdad, demanding that U.S. troops leave Iraq, observers said.

The demonstration Thursday was called by radical anti-American cleric Moqtada Sadr, who threatened last month to end a 2007 cease-fire and "escalate armed resistance" if U.S. troops remain after the deadline to withdraw American troops this summer passes, CNN reported.

"Yes, it is a message to end occupation [the demonstration]," said Hazem al-Araji, a senior Sadr aide. "And there will be more parades to put more pressure on the occupiers and the Iraqi government to end the occupation in Iraq."

Al-Sumaria reported Thursday unarmed soldiers were joined by hundreds of supporters chanting "Yes, Yes Zaharaa," "Yes, Yes Islam, "Yes, Yes Iraq" and "No, No USA."

The Aswat al-Iraq news agency said Sadr saluted the protesters from a platform as they marched past in black uniforms with the Iraqi flag on their chests.

Iraqi police and military troops imposed stronger security measures ahead of the parade but otherwise kept a low profile, observers said.

The demonstrations come as Prime Minister Nouri al-Maliki prepared to meet with Iraq's political leadership to discuss extending the presence of U.S. troops beyond the Jan. 1, 2012, withdrawal deadline.