Radical Shiite cleric Muqtada al-Sadr strongly condemned construction of a wall around a Sunni neighborhood in Baghdad, calling for demonstrations against the plan as a sign of "the evil will" of American "occupiers."

The remarks, in a statement read by an aide, were the first by the anti-American cleric since the U.S. military announced last week that it was building a three-mile long, 12-foot high concrete wall in Azamiyah, a Sunni stronghold that has been targeted by mortar and rocket attacks by Shiite militiamen.

Many Sunnis also protested the plan, saying they felt like they were being herded into a prison. Protesters in Azamiyah carried banners Monday with slogans such as "No to the sectarian wall" and "Azamiyah children want to see Baghdad without walls."

In the statement, al-Sadr said the protests showed that Iraqis reject "the sectarian, racist and unjust wall that seeks to divide" Sunnis and Shiites.

"I am confident that such honorable voices will bring down the wall," he said.

Hours after al-Sadr's statement was released, some 5,000 people demonstrated in Baghdad's Shiite neighborhood of Sadr City chanting "no, no to division." Others carried a banner that read "the building of Baghdad wall is the beginning of Baghdad's division."

Al-Sadr, whose Mahdi Army militia was blamed for many of the sectarian killings of Sunnis, has been trying to make overtures to the Sunni minority and draw a difference between ordinary Sunnis and extremists who target Shiites.

"This wall shows the evil will of the occupier and its sectarian and terrorist projects against our people," al-Sadr said in the statement. "We the people of Iraq will defend Azamiyah and other neighborhoods that you (Americans) want to segregate from us. We will stand hand in hand with you (Sunnis) to demonstrate and protect our holy land."

The U.S. and Iraqi military said they plan to construct barriers in other neighborhoods too to protect people from bombings and other sectarian attacks.

A leading Sunni Muslim group, meanwhile, accused the Shiite-led government of turning a blind eye to sectarian death squads allegedly run by the Mahdi Army.

"The return of the militias and death squads to target Sunni areas, the attempts to chain these areas with walls to make them soft targets for militias, and the arrest campaigns against Sunnis, especially mosque imams, are all part of a plan to empty Baghdad of Sunnis," the Conference for the People of Iraq said in a statement.

The group, which is led by prominent Sunni politician Adnan al-Dulaimi, called on the government to stop what it called "sectarian projects" that target Sunnis, warning "our patience is running out."

On Sunday, Prime Minister Nouri al-Maliki said he would not allow "a separation wall," but then he said that the subject would be discussed. He said he would not rule out all barriers, such as barbed wire.

Al-Maliki told reporters Wednesday before leaving Kuwait to Oman that "I order a cease in the construction of the wall and when I go back we will take a decision." He did not elaborate.

Following al-Maliki's comments, the new American ambassador to Iraq, Ryan Crocker defended the barrier plan, saying it was an effort to protect the Sunni community from surrounding Shiite areas, not to segregate it. But he also indicated security measures could be reconsidered, saying they were implemented in coordination with the Iraqi government.

"Obviously, we will respect the wishes of the government and the prime minister," Crocker said, although he did not say construction would halt.

Iraq's chief military spokesman Qassim al-Moussawi indicated that some type of barrier would go up, saying al-Maliki was responding to exaggerated reports about the wall.

An aide to al-Sadr, Sheik Salah al-Obaidi, told reporters in the Shiite holy city of Najaf that two demonstrations were planned in eastern and western Baghdad to condemn the wall. He did not give a date for the demonstrations but said that if the security situation permits, al-Sadr's followers will be happy to join demonstrators in Azamiyah.

The U.S. military has said that al-Sadr is currently in neighboring Iran, a claim that his aides denied in the past week saying he is in Iraq.

Al-Obaidi said al-Sadr's disappearance "is for security reasons and ... it is not necessary to know where he is. Sayyed Muqtada is with the people and feels their suffering."

The Mahdi Army, that launched two uprising against U.S. troops in 2004, has been one of the main targets of a security plan in Baghdad launched more than two months ago.

Last week, al-Sadr ordered his six Cabinet ministers to leave the government after al-Maliki refused to put a timetable for foreign troops withdrawal.