TIKRIT, Iraq, June 21 (Xinhuanet) -- Two suicide car bomb attacks targeted two Iraqi army checkpoints north of Baghdad, killing six Iraqi soldiers and wounding several others, the US-Iraqi joint coordination center said on Tuesday.

    "A suicide car bomber drove an explosive-laden vehicle into an Iraqi army checkpoint in Pingijan village, some 70 km east of Tikrit," the centre said in a statement.

    The attack took place late on Monday night, killing four Iraqi soldiers and wounding five others, it added.

    According to the statement, "another suicide car bomber attacked another military checkpoint on the road between Tikrit and Tuz Khurmato, killing two soldiers and injuring another."

    On Monday, insurgents in Iraq stepped up attacks on security forces detonating six car bombs, including a suicide car bombing in the northern Iraqi city of Arbil, killing dozens of Iraqis, most of them were policemen. Enditem