Egyptian security officials say gunmen have opened fire on an army bus in Cairo, killing one officer and wounding three soldiers. The officials say the bus, which belongs to the army’s Military Police, was driving through the capital’s Amiriyah district when it was targeted on Thursday morning. The officials did not say who was responsible for the attack, which bore the hallmarks of Islamic militants. In the eight months since the ouster of Egypt’s Islamist President Mohammed Morsi, militants have targeted the military and police forces in Cairo and elsewhere in the country, often using motorbikes. Militants also are waging a full-fledged insurgency in the strategic Sinai Peninsula. The officials spoke on condition of anonymity because they were not authorized to speak to the media.