Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Australian Police Foil Christmas Day 'Terror Plot' by Phil Mercer SYDNEY -- Police in Australia say they have prevented a terror attack planned for the city of Melbourne on Christmas Day. Five men are in custody. The suspects were arrested at properties in suburban Melbourne in the Australian state of Victoria. Four of them were Australian-born men in their 20s of a Lebanese background, while another was an Australian of Egyptian origin. Another man and a woman were detained in the raids, but have been released without charge. Police have said the alleged plot was inspired by the Islamic State militant group. Victorian Premier Daniel Andrews described the conspiracy as an "act of evil," while investigators said they had seized "the makings of an improvised explosive device." It is alleged the threat was to prominent locations in Melbourne, Australia's second biggest city, including Flinders Street Station and St. Paul's Cathedral. Australian Prime Minister Malcolm Turnbull said a violent terrorist conspiracy had been disrupted. He added that the international threat of extremism was rising. "We see around the world the global threat of terrorism; the truck attack in Berlin earlier this week and similar attacks - terrorist attacks - in so many other places just in the last few weeks, including Nigeria, Yemen, Turkey, Somalia, Egypt and Jordan. Islamist terrorism is a global challenge that affects us all, but we must not be cowed by the terrorists," said Turnbull. The arrests follow a long investigation by Victoria Police, the Australian Federal Police and the security agencies. Security will be increased at prominent locations around Melbourne, including the Boxing Day cricket test between Australia and Pakistan, which will attract a crowd of around 100,000 people. Australia's official domestic terrorism threat level remains at probable, which indicates individuals or groups have the intent and capability to conduct an attack on home soil.