A local police chief, Mohammad Nabi, said the bomb went off along a road north of the city of Kandahar as the police officers were passing in a vehicle.
He blamed Taliban insurgents for the blast.
The Taliban, which has been battling U.S. and government forces since they were ousted in 2001, have claimed responsibility for most of a recent wave of blasts in southern and eastern Afghanistan.
At least 28 people were killed on 3-4 February in fighting between Taliban insurgents and police and Afghan soldiers in the southern province of Helmand.
RFE/RL Afghanistan Report
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