Aftermath of car bomb (AP Photo)

A car bomb ripped through a wholesale food market in western Baghdad on Sunday, flattening cars and shops and killing at least 30 people in the deadliest of a wave of attacks across Iraq that killed at least 50 people.

The attack came amid an 11-week-old crackdown by U.S.-led forces intended to bring stability to Baghdad.

As part of that crackdown, U.S. and Iraqi forces raided the Shiite neighborhood of Sadr City early Sunday, uncovering a weapons cache, a torture room and killing at least eight insurgents in a gunbattle, the military said.

In other violence, three U.S. troops were killed in separate attacks, the military said Sunday.

Two Marines were killed Saturday in fighting in Anbar province, a Sunni insurgent stronghold west of Baghdad, and a roadside bomb killed a soldier and wounded four others Friday in western Baghdad, the military said. The deaths raised to at least 3,365 members of the U.S. military who have died since the Iraq war started in March 2003, according to an Associated Press count.

The market blast Sunday erupted about noon in the mixed Sunni-Shiite Baiyaa neighborhood and devastated the area, reducing cars and trucks to their charred skeletons and ripping the roofs and exteriors off shops. In addition to the dead, dozens were injured.

Blood pooled in the dirt streets. Hospital officials said two pickup trucks filled with body parts were brought to the morgue.

"I was waiting near a shop to lift some boxes, when I saw the owner of the shop fall down," said Satar Hussein, 22, a worker in the market. "I helped him inside the shop, but he was already dead. The next thing I felt was pain in my left shoulder and some people rushing me to the hospital."

Ali Hamid, 25, the owner of a food store, said he was selling boxes of Pepsi when he was hit with shrapnel in his hand.

"I fainted, and the next thing I remember is some people putting me in a pickup with two dead bodies and rushing me to the hospital," he said, condemning the attack as "a terrorist act aiming at creating more sectarian tension and strife."

No one immediately claimed responsibility for the attack in Baiyaa, the scene of frequent sectarian violence including a bombing and mortar attack last week that killed seven people.

In an effort to strike at insurgents, U.S. troops led an early morning raid into Sadr City and were attacked by militants armed with rifles and rockets who were hiding in a building. Four other armed men attacked them from behind a car, and the troops again returned fire, destroying the car, the military said.

The troops had targeted four buildings in the area based on intelligence indicating the presence of an insurgent cell that smuggled weapons — including powerful roadside bombs known as "explosively formed penetrators" — from Iran, sent fighters to the neighboring country for training and was involved in a kidnapping network, the military said.

The target of the raid was not found, said Maj. Gen. William Caldwell, the chief U.S. military spokesman.

In one of the buildings they searched, the forces uncovered a large cache of weapons, including more than 150 mortar rounds, and a torture room, replete with several sets of handcuffs and a mask, he said. Soldiers decided to destroy the building rather than risk moving the explosives and accidentally setting them off, he said.

"The extensive damage it would have done in killing innocent civilians in Sadr City would have been horrific," he said.

Footage taken by AP Television News, showed the building reduced to piles of brick and rubble.

In other violence Sunday, a car bomb near the Ministry of Labor in Baghdad killed five people and wounded 10, police said.

Insurgents exploded another car bomb outside a police station in the Sunni town of Samarra, about 60 miles north of Baghdad, killing four police and a bystander, police said. A few minutes later, militants in the town attacked a police checkpoint near the Askariya shrine, killing another police officer, police said.

It was the bombing that devastated the golden dome of the Shiite mosque on Feb. 22, 2006, that set of a cycle of retaliatory sectarian violence that U.S.-Iraqi forces are struggling to curb.