KABUL, Afghanistan (AP) — An Afghan policeman hurled a grenade and opened fire on a U.S. military foot patrol in eastern Afghanistan on Thursday, killing an American soldier and raising fears that insurgents have infiltrated the police. It was the second attack by a policeman on U.S. soldiers in eastern Afghanistan in less than a month. The patrol was returning to a base in Bermel district of Paktika province when they were attacked by the policeman, who was standing on a tower, the military said. The soldiers returned fire, killing the officer.—-Contact The Daily Reveille’s news staff at [email protected]