Australian troops in southern Afghanistan are on alert after three fellow soldiers were shot dead and seven wounded by a gunman wearing an Afghan army uniform. An Afghan interpreter was also killed in the incident, which happened during a routine morning parade at Shah Wali Kot in the southern province of Kandahar. The attacker was shot dead moments later when troops returned fire. The troops have been placed on a heightened security alert, as a precaution against any further attacks. Afghan and Australian commanders have visited the site of the attack to assist in the response and offer support to the survivors. Australian army cook Lance Corporal Andrew Jones was shot dead by an Afghan soldier in May. A total of 33 Australians have now been killed in Afghanistan.