Insurgent attacks in several parts of Afghanistan have killed 10 police officers over 24 hours, officials said Wednesday. In the south, four officers were killed when they responded to an explosion in Musa Qala district on Wednesday, said provincial spokesman Daoud Ahmadi. No one was killed in the first blast, but a second, apparently remote-controlled, bomb hit the policemen when they got to the scene to investigate. In Herat province in the west, an ambush killed four policemen on patrol in Ghoryan district late Tuesday, said provincial government spokesman Noor Khan. Also, in Kunduz province in the north, two police officers were killed when their truck hit a roadside bomb early Wednesday, Kunduz province police chief Gen. Samihullah Qatrah was quoted as saying by the Associated Press.