NEW : Taliban used grenades , dragged bodies through villages , official says . NEW : U.S. believes Taliban planned attack expecting U.S. to send in reinforcements . Civilians killed in US airstrikes in Afghanistan , Red Cross says . News of strike comes as Afghan president visiting Washington for vacation .
NEW : Taliban used grenades , paraded bodies through villages , official says . NEW : U.S. believes Taliban planned attack expecting U.S. to call in airstrikes . Civilians killed in U.S. airstrikes in Afghanistan , Red Cross says . News of strike comes as Afghan president visiting Washington for talks .