SYDNEY, Nov 20 (Reuters) - Australian police on Tuesday said they had arrested three men who were allegedly preparing to make a terrorist attack in Melbourne, just weeks after a man killed one person in the city in what police said was an act of terrorism.
Australian federal and state police, the Australian Security Intelligence Organisation (ASIO), and other agencies which form part of the Joint Counter Terrorism Team carried out the arrests on Tuesday morning.
The ongoing sweep, named Operation Donabate, was in the northwest region of the city and included four search warrants. Three men, aged 30, 26 and 21, were taken into custody.
"It will be alleged the three men arrested were involved in undertaking preparations for planning a terrorist act in Melbourne," police said in a statement.
Australia, a staunch U.S. ally that sent troops to Afghanistan and Iraq, has been on heightened alert since 2014 for attacks by home-grown militants returning from fighting in the Middle East or their supporters.
Earlier this month, a Somali-born man set fire to a pickup truck laden with gas cylinders in the centre of Melbourne and stabbed three people, killing one, before he was shot by police.
Islamic State claimed responsibility for that attack, without providing any evidence.