BAGHDAD, Feb. 21 (Xinhua) -- A series of bomb attacks, including a suicide one, in Iraq's Baghdad and southern city of Najaf killed altogether 14 people and wounded 69 others on Wednesday.

    A suicide car bomber hit an Iraqi security checkpoint at the entrance of the busy commercial neighborhood of Najaf's old city, some 160 km south of Baghdad, killed up to 11 people and wounding 34 others, local police source told Xinhua on condition of anonymity.

    "Security members suspected the car bomb and ordered the driver to stop, prompting the suicide bomber to blew up his car," the source said.

    An early report said that a suicide car bomb blasted caused the mayhem in the holy Shiite city of Najaf, killing eight people and wounding 34 others.

    Earlier in the day, a car bomb went off near a petrol station in Baghdad's southern district of Baiyaa, killing two people and wounding up to 30 others, according to an Interior Ministry source.

    In separate incident, a roadside bomb went off near a passing police commando patrol on the Jadriyah Bridge in southern Baghdad, damaging a police vehicle, killing a commando member and wounding three others aboard, the police said.

    In central Baghdad, a mortar round landed on the entrance of the large parking lot of Alawi area, wounding two people, the police added.

    Violence shows no sign of abating despite a security clampdown, dubbed "Operation Imposing Law", launched by U.S. and Iraqi troops in Baghdad. Dozens of people had been killed in a wave of bombings on Tuesday.