A car bomb struck a US military convoy in southern Baghdad on Wednesday, causing casualties, police said.

The blast took place at around 11:00 a.m. (0700 GMT) on the highway in al-Jadida district, and US troops cordoned off the area, an Interior Ministry source told Xinhua on condition of anonymity.

The source said there were no civilian casualties and it was hard to know casualties of the US soldiers.

The US military did not confirm the attack.

In a separate incident, a suicide bomber failed to blow up his car near a US military convoy and US soldiers captured a Syrian national, the source quoted a US military officer as saying.

"A suicide car bomber drove his explosive-packed BMW car to a US military convoy but failed to blow up the charges. One tank in the convoy ran over his car but the charges did not blow up," the source said.

The failed attack took place on a highway in eastern Baghdad, the source said.

The latest two car bombs brought the number of car bombings on Wednesday to six.

Source: Xinhua