Terrorism in Australia deals with terrorist acts in Australia as well as steps taken by the Australian government to counter the threat of terrorism. In 2004 the Australian government has identified transnational terrorism as also a threat to Australia and to Australian citizens overseas. Australia has experienced acts of modern terrorism since the 1960s, while the federal parliament, since the 1970s, has enacted legislation seeking to target terrorism. Terrorism is defined as "an action or threat of action where the action causes certain defined forms of harm or interference and the action is done or the threat is made with the intention of advancing a political, religious and ideological or group cause". Notable terrorist attacks in Australia Terrorists attacks have occurred in Australia over the country's history, including the following notable incidents. Battle of Broken Hill (1915) Two men shot dead four people and wounded seven more, before being killed by police and military officers. At the time of their attack, they raised the flag of the Ottoman Caliphate, later the Turkish flag to identify their cause. Neither of the men were members of any official armed force. In today's parlance, their attack would be described as an act of a lone wolf. The two men were later identified as being Muslims from the British colony of India, modern-day Pakistan (some sources incorrectly identify them as Turkish). Soviet Embassy bombing (1971) The Embassy of the USSR was attacked by a crude bomb on 17 January 1971 in Canberra. Sydney Yugoslav General Trade and Tourist Agency bombing (1972) The Sydney Yugoslav General Trade and Tourist Agency bombing occurred in Haymarket, Sydney on 16 September 1972; the attack injured sixteen people. The perpetrators of the attack were believed to be Croatian separatists. Sydney Hilton Hotel bombing (1978) The Sydney Hilton Hotel bombing occurred on 13 February 1978; a bomb exploded outside the Hilton Hotel in Sydney, which was hosting the first Commonwealth Heads of Government Regional Meeting. Two garbage collectors and a police officer were killed and eleven others were injured. Family Court of Australia attacks (1980–1985) On 23 June 1980, David Opas, a judge of the Family Court, was shot dead outside his home. In March 1984, a bomb destroyed the home of fellow judge Richard Gee, who survived. In April, a bomb exploded in the Family Court building in Parramatta. In July, the wife of judge Ray Watson was killed