The US military on Sunday announced the deaths of seven more troops in Iraq, including four killed by a roadside bomb while patrolling western Baghdad - the latest American casualties in a month-long security crackdown in the capital. Though violence has receded slightly in the capital, a car bomb killed seven Iraqis in a predominantly Shiite district on Sunday, police said. The attack targeted people cooking food at open-air grills in the street, to offer as charity on a Shiite Muslim holiday. Police said 26 others were wounded in the attack. A US official, meanwhile, blamed al-Qaida in Iraq for chlorine bomb attacks that struck villagers in Anbar province earlier this week but said tight Iraqi security measures prevented a higher number of casualties. Three suicide bombers driving trucks rigged with tanks of toxic chlorine gas struck targets in the insurgent stronghold including the office of a Sunni tribal leader opposed to al-Qaida. The attacks killed at least two people and sickened 350 Iraqi civilians and six US troops, the US military said Saturday. US military spokesman Adm. Mark Fox said at least one of the attackers detonated his explosives after he was unable to get past an Iraqi police checkpoint in Amiriyah, just south of Fallujah, killing only himself. Fox conceded that many Iraqis were exposed to the chemical fumes but insisted that steps Iraqi security forces were increasingly effective. "Insurgent attempts to create high-profile carnage are being stopped at checkpoints across the country," he said at a news conference in Baghdad. Iraqi government spokesman Ali al-Dabbagh appealed to Iraqis to help stop the violence. "Opportunity is still available to all honest Iraqis to rescue this country from the criminals," he said at a joint news conference with Fox. "The chlorine attack was a kind of punishment against the people who stood against terrorist organizations." There is a growing power struggle between insurgents and the growing number of Sunnis who oppose them in Anbar, the center of the Sunni insurgency, which stretches from Baghdad to the borders with Syria, Saudi Arabia and Jordan. The Anbar assaults came three days after Prime Minister Nouri al-Maliki, a Shiite, traveled there, hoping to reach out to Sunni clan chiefs and to undermine tribal support for the insurgency. After the explosion that killed four US soldiers on Saturday, the unit came under fire and another soldier was wounded. During this month's crackdown in the capital, the battalion had found eight weapons caches and two roadside bombs and helped rescue a kidnap victim, the military said. An explosion in Diyala province northeast of Baghdad killed another soldier Saturday and injured five. A sixth soldier died Saturday in a non-combat related incident, the military said. A US Marine also was killed Saturday in fighting in Anbar, according to a separate statement. Saturday's deaths brought to at least 3,217 members of the US military who have died since the Iraq war started in March 2003, according to an Associated Press count. A Web video surfaced Sunday showing an alleged insurgent crawling under a US military vehicle in Iraq and purportedly planting explosives in full daylight. Seconds later, the video cuts to an explosion ripping the vehicle apart. The footage was stamped with the emblem of the Islamic State of Iraq, an al-Qaida-linked militant group that disavows Iraq's elected government and seeks to establish Muslim law. The video was posted on an Islamic Web site that frequently airs insurgent messages, but its contents and authenticity could not be independently verified. The footage shows a man in beige pants and a dark sweatshirt, crawling through mud puddles underneath a Bradley fighting vehicle and hauling an object about two feet long. Then the video switches to a wider view of the vehicle exploding in a ball of flames and smoke. A caption says the incident happened in western Anbar province, an insurgent stronghold west of Baghdad. In violence Sunday, gunmen opened fire on a minibus carrying civilians northeast of Baghdad, killing seven men and wounding four others, police said. The attack occurred in Hibhib, just east of Baqouba, in the area where al-Qaida in Iraqi leader Abu Musab al-Zarqawi was killed in a US airstrike on June 7. A roadside bomb also hit an Iraqi police convoy in eastern Baghdad, killing two policemen and wounding five, authorities said. Later, police said a mortar round landed near a house in central Baghdad, killing a civilian and wounding another. In Shorja market, Baghdad's most popular central shopping district, a man tossed a grenade into a group of workers, police said. One worker was killed and another was wounded. The suspect escaped through an alley, they said. The Shorja market, which has been attacked several times, was turned into a pedestrian zone after a US-Iraqi security crackdown began in Baghdad on Feb. 14. An abandoned hotel exploded Sunday in an industrial area of Fallujah, 65 kilometers west of Baghdad. Police said insurgents had planted bombs in the three-story building and then detonated it at dawn. Half of the building was destroyed. Iraqi troops had taken over part of the building's roof as a base, police said. There were no reports of casualties. In Diwaniyah, 130 kilometers south of Baghdad, fierce fighting erupted between US troops and elements of the Shiite Mahdi Army, police said. There were no reports of casualties, and the US military had no immediate comment. Eleven bodies were found - six in Baqouba, in Diwaniyah and four in Mosul - many with signs of torture and all apparently victims of sectarian killings. Meanwhile, the US military said American troops captured 12 suspected militants Sunday in raids across Iraq, all accused of plotting attacks on US troops. Fox, the US military spokesman, also said Iraqi forces acting on a tip found a huge weapons cache Friday on the outskirts of the northern city of Mosul, including 1,800 pounds of bulk explosives. He said the military was seeing "glimmers of good signs" in the security sweep that began in mid-February to quell sectarian violence in Baghdad.