KABUL, Afghanistan — Scores of Afghan security forces were killed Monday when a suicide bomber in a Humvee rammed a training compound of the national intelligence agency in Wardak Province, officials there said. The Taliban insurgents immediately claimed responsibility for the attack. Security officials in Kabul speaking on the condition of anonymity, told news agencies that the death toll could reach higher than 120, with a large number wounded. The massive bombing destroyed most of the building in the provincial capital where about 150 counterinsurgency troops are based, officials there said.