KABUL: A bomb stuck onto a car killed a civilian in downtown Kabul, Afghan police said.

However, authorities were unclear as to the motives for the attack.

Deputy Interior Ministry spokesman Najib Dunish said Monday's explosion was caused by a magnetic bomb attached to a car as it drove through Kabul.

Dunish said the police were unsure if the bomb was planted by insurgents or if it was placed by criminals who had differences with the driver.

Roadside bombs and improvised explosive devices are the top killers of Afghan civilians and security forces.

Insurgents have been blamed for the overwhelming majority of bomb attacks in Afghanistan.