U.S. officials signaled Monday that they might reconsider the construction of a sharply contested concrete barrier surrounding a Sunni neighborhood in Baghdad after the prime minister ordered the project halted as he faced strong political pressure from Sunnis.

In a fresh example of the style of attacks the military has said it is aiming to prevent with such walls, homicide bombers killed at least 46 people in five attacks in Baghdad and surrounding areas.

The deadliest strike occurred when a homicide car bomber struck near a restaurant outside Ramadi, killing at least 19 people and wounding 35 about an hour after a similar attack targeting Iraqi police in the volatile city wounded seven people.

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Any plan to build "gated communities" to protect Baghdad neighborhoods from sectarian attacks was in doubt after Prime Minister Nouri al-Maliki said Sunday during a visit to Sunni-led Arab countries that he did not want the 12-foot high wall in Azamiyah to be seen as dividing the capital's sects.

But hundreds of protesters took to the streets of Azamiyah — a Sunni stronghold whose residents have often been the victims of retaliatory mortar attacks by Shiite militants following bombings usually blamed on Sunni insurgents — to oppose what they called "a big prison."

The new American ambassador to Iraq, Ryan Crocker, defended the plans for the five kilometer (three-mile) wall being erected in the northern enclave of Azamiyah, a day after Prime Minister Nouri al-Maliki demanded called for construction to stop.

Crocker, in his first news conference since assuming the post, said the measure was an effort to protect the Sunni community from surrounding Shiite areas, not to segregate it.

He said security measures were implemented in coordination with the Iraqi government and "obviously we will respect the wishes of the government and the prime minister," although he did not say construction would be halted.

Al-Maliki ordered a halt to the construction of the wall Sunday during a televised live news conference during a state visit to Cairo, Egypt, saying "there are other methods to protect neighborhoods."

He reiterated the call on Monday, despite assertions by an Iraqi military spokesman that erection of the barrier would continue.

"The construction of the wall might be misunderstood to be targeting a certain group," al-Maliki told reporters in Cairo. "It should be stopped. We should try to find an alternative."

The Shiite prime minister, however, said he would not allow "a separation wall," although he acknowledged there would be heavy debate on the subject and would not rule out "barbed wire."

His comments came even as chief Iraqi military spokesman Brig. Gen. Qassim al-Moussawi saying al-Maliki was responding to exaggerated reports about the barrier.

"We will continue to construct the security barriers in the Azamiyah neighborhood. This is a technical issue," al-Moussawi said at a joint news conference with U.S. military spokesman Rear. Adm. Mark Fox. "Setting up barriers is one thing and building barriers is another. These are moveable barriers that can be removed."

Al-Moussawi noted similar walls were in place elsewhere in the capital — including in other residential neighborhoods — and criticized the media for focusing on Azamiyah.

Al-Maliki's comments came as he faces heavy pressure to bring Sunnis into the political process and dampen support for the insurgency amid unrelenting violence nearly 10 weeks into a security crackdown in Baghdad.

But Sunni Arabs, who were dominant under Saddam Hussein but lost power after the U.S.-led invasion four years ago, remain deeply distrustful of al-Maliki's intentions.

Protesters in Azamiyah carried banners with slogans such as "No to the sectarian wall" and "Azamiyah children want to see Baghdad without walls" as they marched from amosque to a nearby former Iraqi police station that now houses an outpost of U.S. soldiers.

"The real reason behind this wall is to increase peoples' sufferings and complicate their daily lives," said one of the protesters, Iraqi engineer Khalil al-Obaidi.

Sheikh Sameer al-Sumaidaie, an imam and preacher at the mosque where the protest started, said: "We had a united country before the war, but now it is being divided into fragments."

The prime minister had assured the Americans that he would not allow political consideration to influence tactical decisions, but his criticism of the wall followed a wave of outrage from residents and Sunni leaders after the U.S. military announced its plans last week.

The confusion reflected a lack of coordination between al-Maliki's government and the U.S. military even as they have touted their partnership in a nearly 10-week security effort to pacify Baghdad.

Lt. Col. Christopher Garver, a U.S. military spokesman, indicated that there may have been a miscommunication.

"Discussions on a local level may not have been conveyed to the highest levels of the Iraqi government," Garver said. "Whether the prime minister saw this plan or not, I don't know. With him in Cairo, it complicates things."

Al-Maliki has countered U.S. plans in the past. In October, U.S. forces pulled down roadblocks around Baghdad's Shiite slum of Sadr City hours after al-Maliki gave the order. At the time, the prime minister was said to have feared violence among members of the Mahdi Army, the Shiite militia that is headquartered in Sadr City and loyal to the anti-American cleric Muqtada al-Sadr.

But he is currently under intense pressure from the Bush administration to show progress with security and national reconciliation efforts as the war grows increasingly unpopular in the United States.

In Washington, Democratic Senate Majority Leader Harry Reid said Congress will ignore a presidential veto threat and pass legislation within days requiring the withdrawal of American combat troops from Iraq beginning Oct. 1, with a goal of completing the pullout six months later.

U.S. President George W. Bush promised to reject any legislation along the lines of what Democrats intend to pass.

I will strongly reject an artificial timetable (for) withdrawal and/or Washington politicians trying to tell those who wear the uniform how to do their job," the president said as confrontation intensifies over a war that has taken the lives of more than 3,200 U.S. troops.

A U.S. soldier also was killed Monday when a roadside bomb exploded near him in Muqdadiyah, about 60 miles north of Baghdad, the military said. A British soldier was shot to death while on patrol in the southern city of Basra, officials said.

In all, at least 68 people were killed or found dead in Iraq.

Complete coverage is available in FOXNews.com's Iraq Center.