A dispute between a United States Marine and an Afghan policeman turned deadly Saturday, while a bicycle bomb wounded 10 people, including four policemen.
NATO officials say the first incident took place at a patrol base in Helmand province, when the Marine and the Afghan officer got into an argument.
The Marine told officials the police officer threatened him, and was handling his weapon in a reckless manner. The Marine said he shot the Afghan officer only after the man pointed the gun at him.
NATO is investigating the shooting.
Meanwhile, a bicycle bomb in the southern city of Kandahar wounded four Afghan police officers and six civilians.
Police said the bomb detonated near the center of the city.
A separate bombing in Daykundi province killed three Afghan civilians and seriously wounded a fourth.
NATO says the vehicle the civilians were riding in hit a roadside bomb. NATO also said its forces helped kill several insurgents Saturday in a series of operations across the southern part of the country.
Some information for this report was provided by AP and Reuters.