BAGHDAD, Jan. 2 (Xinhuanet) -- A suicide car bomber hit a bus carrying Iraqi National Guards on Sunday, killing at least 23 people, in an attack obviously against Iraqi cooperation with US forces to secure the Jan. 30 elections.

    The attacker rammed an explosives-packed car into the bus and blew it up outside a US military base in Balad, 80 km north of Baghdad.

    US military officials said 18 Iraqi guardsmen and a civilian bystander were killed on the spot and four more guardsmen died of their wounds later.

    They also said they were not sure if there were one or two bombers inside the car that hit the bus.

    This suicide bombing is the deadliest against Iraqi security forces since mid-September, when at least 47 people were killed outside a Baghdad police station.

    With elections just weeks away, Iraq is facing serious securityproblems, especially in the so-called Sunni Triangle area north and west of Baghdad, as well as in the capital itself.

    Despite increasing terrorist attacks, the US and the Iraqi interim government are determined to hold national elections in the country as scheduled.

    US Secretary of State Colin Powell urged the interim Iraqi government to speed up efforts to build a stronger security force to help bolster security.

    The United States has now deployed about 150,000 troops in Iraqsince the US-led invasion of Iraq in March 2003. Enditem