An Afghan police official says the Taliban have ambushed a police convoy in the south, killing a district police chief.

The police official says the ambush took place in Helmand province early on Wednesday morning and that the Marjah police chief, Hajji Tooryalai Jan, died instantly in the attack. The police chief's bodyguard was wounded.

The police official giving the details of the attack spoke on condition of anonymity because he was not authorized to speak to the media.

In recent years, Marjah district has been the scene of some of the largest joint assaults on Taliban strongholds by U.S. and Afghan troops.

But the insurgents still have a strong presence in much of southern Afghanistan, the birthplace of the Taliban, despite heavy deployments of international troops.