A suicide car bomber struck a busy Baghdad commercial district Monday, killing at least 21 people, setting cars on fire and damaging a nearby Sunni shrine, police and hospital officials said. The blast went off at 2 p.m. in the Sinak market area on the east side of the Tigris River, just as US and Iranian diplomats were wrapping up a historic meeting aimed at ending the violence wracking the country. Insurgents carried out several mortar and car bombing attacks throughout the capital Monday and even waged a lengthy gun battle with police in broad daylight. The wave of violence, which killed 36 people across Baghdad, came despite a nearly 15-week-old US-led security crackdown in the city. The deadliest attack Monday was the car bombing in the Sinak district, near the Abdul-Qadir al-Gailani mosque. AP Television News footage showed dozens of astonished people wandering among the scorched cars and debris that littered the scene. Firefighters in yellow helmets struggled to extinguish the fire as ambulances rushed to evacuate the wounded. The television footage showed damage to the mosque's minaret, while the cleric in charge of the Sunni shrine, Mahmoud al-Issawi, said the blast damaged the building's dome as well. "The enemies of Iraq are the only ones who benefit from this bombing. These enemies have targeted our homeland, religion and our brotherhood," Issawi told Iraqiya TV. The blast also wounded 66, including three traffic policemen. Earlier Monday, a battle raged between militants and police in the narrow alleys of another central Baghdad neighborhood after insurgents hijacked two minibuses and kidnapped at least 15 passengers, police said. At least three policemen were killed and eight other people were wounded in the fighting, authorities said. The buses were traveling from Baghdad's main bus station to the city's eastern Shi'ite neighborhoods about 10:15 a.m. when gunmen in three cars forced them to stop as they passed through the Sunni enclave of Fadhil. The attackers took the passengers to a nearby abandoned medical center. A gun battle broke out when Iraqi security forces arrived 30 minutes later, police said. Nine militants were arrested as they attacked security forces from nearby alleys with light weapons. At least two US helicopters hovered overhead and US forces took up positions near the fighting, but were not directly involved, police said. After 45 minutes, Iraqi security forces stormed the building, but the militants had already left, apparently with their hostages, police said. In other attacks, a rocket landed near a gas station in the Shi'ite-dominated Baghdad neighborhood of Karrada on Monday afternoon, killing four people and wounding three others, police said. Hours earlier, two mortars slammed into a Karrada street, killing two people and wounding six others, police said. A parked car bomb ripped through an outdoor market in southeastern Baghdad's Zafaraniyah neighborhood Monday evening, killing 3 civilians and wounding 10 others, police said. A roadside bomb killed two people and injured another nine when it detonated under a parked car in the central Baghdad district of Bab al-Muadham, and a sniper targeting the entrance to Mustansiriyah University in eastern Baghdad killed a female student, police said. Attacks on Iraqi security continued Monday, with two police officers in the northern city of Mosul killed in a suicide bombing and a police officer in Basra killed in a drive-by shooting, police said.