A homicide car bomber struck Monday at a checkpoint near the entrance to the Green Zone (search) that houses Iraq's interim government and foreign embassies, a police commander said. At least 13 people were injured in the attack, hospital sources said.

A police officer who declined to be identified said the blast occurred when a car that had been waiting in line to enter the zone at the western Harthiyah gate exploded as it drove up to the checkpoint. Several other vehicles were also destroyed in the blast.

"So far we have received 13 injured," said Mohamed Salaheddin, a doctor the Yarmouk Hospital in western Baghdad.

The international zone has been the scene of frequent attacks by insurgents over the past 18 months.