NATO says a coalition and Afghan forces have killed 10 insurgents in a raid on a narcotics laboratory in southern Afghanistan, while militants have killed three NATO troops in separate incidents.

NATO said Sunday the joint force of coalition and Afghan troops raided the narcotics laboratory a day earlier in the Baghran district of Helmand province. It says the troops exchanged fire with militants at the facility before destroying it. NATO says it was one of the largest heroin-producing laboratories to be destroyed in Afghanistan in the past five years.

The alliance also says roadside bombings killed two of its troops in southern Afghanistan on Sunday, while a third attack in the south killed a coalition service member on Saturday. It did not disclose the nationality of the coalition personnel.

The Afghan Interior Ministry said government forces and their NATO allies killed 49 insurgents and detained 25 others in a series of battles around Afghanistan since Saturday. It says two Afghan policemen also were killed in the fighting.

Elsewhere, Afghan officials say a rocket struck a school in the eastern province of Logar on Sunday, killing a boy and wounding 10 other students. It was not clear who fired the rocket.