The U.S. military says four car bombings in the Iraqi capital Wednesday, killed at least 26 people and wounded more than 20 others.

A statement said the bombings occurred within a span of 90 minutes and that security forces prevented the suicide bombers from reaching their intended targets.

Two Iraqis were killed and two Australian solders wounded in the first blast near the Australian embassy.

Shortly afterwards, a car bomb exploded near a central Baghdad hospital, killing at least 18 people, including five Iraqi policemen.

Two other car bombings killed Iraqi soldiers, security guards and civilians.

Iraq said Tuesday it will close its borders and ban non-governmental vehicles from the roads to boost security for the country's January 30 election.