An Afghan police official says one person died and three were wounded when their vehicle struck a roadside bomb in the capital, Kabul.

Hashmat Stanikzai, the spokesman for the Kabul police chief, says a woman was among the wounded when the explosion happened early Tuesday.

He says the victims were all civilians and their vehicle was destroyed in the blast. The Taliban have claimed responsibility.

In other violence, deputy police chief Pacha Gul Bakhtyar says a policeman opened fire, killing two colleagues, including a district chief and a police unit commander, late on Monday. The attack happened in Nowzad district in southern Helmand province.

The local government says in a statement that three other policemen were wounded. It says the attacker was shot and later died.