WASHINGTON – In the latest likely case of an insider attack, an American service member was killed and several others injured Monday when individuals dressed in Afghan police uniforms turned their guns on them in southern Afghanistan, U.S. officials said.

Jamie Graybeal, a spokesman for the International Security Assistance Force in Afghanistan, confirmed the death and said that the three Afghan shooters fled and are being sought. Although they were wearing police uniforms, it was not yet certain if they were actually Afghan police or were just wearing the clothing.

Other U.S. officials said that nine U.S. troops were injured in the shooting, mostly with fairly minor wounds. The officials spoke on condition of anonymity to discuss an investigation.