Residents gather at the scene of a car bomb attack in Baghdad's Sadr City, April 18, 2007. At least 144 people were killed and more than 230 others injured when a series of bombs rocked Baghdad Wednesday. (Xinhua Photo)

At least 144 people were killed and more than 230 others injured when a series of bombs rocked Baghdad Wednesday, the deadliest day in the capital since the launch of a massive crackdown by U.S. and Iraqi forces two months ago.

In the deadliest attack, an explosive-laden truck went off at a busy commercial street in downtown Baghdad, killing at least 110 people and wounding 160 others, an Interior Ministry told Xinhua.

The powerful blast occurred at about 4:15 p.m. (1215 GMT) at the busy Kifah Street near the Sadriyah neighborhood, which located on the eastern side of the Tigris River.

A Xinhua correspondent nearby saw a thick, dark plume of smoke rising from the area seconds after the explosion, which dispersed half an hour later. Television footage showed that several cars were ablaze while rescue workers tried to evacuate the wounded.

On February 3, the area was hit by a truck bombing, leaving at least 95 people killed and 200 others wounded.

About one hour earlier, a suicide bomber rammed a bomb-rigged car into an Iraqi army checkpoint at the entrance of Sadr City in eastern Baghdad, leaving 20 killed and 51 others wounded.

Most of the victims were civilians as the area was crowded with civilian cars queuing at the checkpoint.

In other violence, 10 people were killed and 12 others wounded when a car bomb ripped through a main road near the private Abdul Majid hospital in Baghdad's central district of Karradah.

A suicide bomber driving an explosive-borne car hit a police patrol around midday in Uwairij area in southern Baghdad, killing two policemen and wounding four people, including two policemen.

In a commercial area in central Baghdad two people were killed and five others wounded when an explosive charge detonated inside a KIA mini-van.

Analysts said the latest string of blasts would definitely undermine the credibility of the ongoing security crackdown, which is widely seen as the last-ditch effort to restore peace and stability in the war-ravaged country while buying time for Prime Minister Nuri al-Maliki to achieve a series of political goals.

The crackdown has been going on for more than two months, but the security situation in Baghdad remains awful. While sectarian attacks and assassinations have declined, relentless car bombs and suicide bombers continue to claim lives of many innocent people.

Wednesday's carnage came two days after the political bloc of anti-American Shiite cleric Muqtada al-Sadr announced to withdraw from the government, which, according to analysts, would impair the power of the Shiite-ruling government and make compromise more difficult.

Also on Wednesday, Iraqi forces took charge of security in the southern province of Maysan, which is the fourth province transferred by the coalition forces since the 2003 U.S.-led invasion.

 
Smoke billows from the site of a car bomb explosion in Baghdad's Sadriyah neighborhood April 18, 2007. The deadly attack left 90 dead and 110 wounded.(Xinhua Photo/Zhang Wei)

Smoke billows from the site of a car bomb explosion in Baghdad's Sadriyah neighborhood April 18, 2007. The deadly attack left 90 dead and 110 wounded. (Xinhua Photo/Zhang Wei)

Editor: Yan