Violence raked Baghdad Monday as an Iraqi general took charge of the security operation in the capital and Iraqi police and soldiers manned new roadblocks initial steps indicating the start of the long-anticipated joint operation with American forces to curb sectarian bloodshed.

But bombers, gunmen and mortar teams appeared undaunted by the push that eventually and on paper will be able to call upon on as many as 90,000 American and Iraqi troops and police in a third bid to calm the capital in nine months.

At least 29 people died in bomb and mortar attacks across the city Monday, 15 of them as they waited to refill propane cooking tanks when two car bombs blew up in quick succession in south Baghdad.

Two past security operations in the capital over the past nine months Operations Together Forward I and II have failed and the United States blamed Iraqi authorities for failing to produce the number of troops promised.

US Defense Secretary Robert Gates said last week that Iraqi troops to augment the newly assembled Baghdad force, while arriving on time, were only at about half the number promised.

A spokesman for the Sadr Movement, an important Shiite bloc in parliament, complained that the security crackdown had been too long in coming, especially given the series of bombings that have devastated mainly Shi'ite marketplaces over the past weeks.

At least 132 people died in a truck bombing on Saturday in the Sadriyah market, the deadliest single bomb attack since the war began.

Falah Hassan, the Sadr bloc lawmaker and spokesman, said the delay "has negative consequences for the lives of the Iraqis."

The security sweep will be led by Lieutenant General Abboud Gambar, who was named to the top position under pressure from the United States military after it rejected Prime Minister Nouri al-Maliki's first choice Lieutenant General Mohan al-Freiji.

Gambar will have two Iraqi deputies, one on each side of the Tigris River that splits Baghdad north to south. The city was to be divided into nine districts, and there were to be as many as 600 US forces in each district to back up Iraqi troops who will take the lead in the security drive.

The security drive, for which US President George W. Bush has dispatched 21,500 additional American forces, was seen by many as a last-chance effort to quell the sectarian violence ravaging the capital and surrounding regions.

As the operation slowly began, suspected Shi'ite militiamen burned down three houses in the largely Sunni al-Amil district in southwest Baghdad. Casualties were not known because police had blockaded the area.

The US military reported the deaths of two American soldiers, both killed on Sunday.

(China Daily via agencies February 6, 2007)