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