A suicide car bomber apparently targeting a senior city official struck an Iraqi military checkpoint Thursday in a Shi'ite neighborhood in Baghdad, killing at least eight people, officials said. Another bomber slammed his explosives-packed car into an army checkpoint in a volatile Sunni district in western Baghdad, killing two people and wounding two others, while a parked car bomb exploded as a bus packed with workers passed by, killing at least four and wounding 24 in Iskandariyah, 50 kilometers south of Baghdad, police said. The blasts came a day after the US military said stopping car bombings had become the main focus of a major security sweep to halt the sectarian violence in the capital. Karradah, a major commercial district, has been hit by bombings several times in recent months, including a suicide car bombings on Jan. 25 that killed 30 people. Elsewhere in Baghdad, the top official in the main Shiite district of Sadr City was seriously wounded when gunmen ambushed his convoy, killing two of his bodyguards, according to police and a local official.