Sydney: Australian Prime Minister Malcolm Turnbull on Saturday said that an attack in Sydney in which a 15-year-old gunman shot dead a civilian police employee appeared to have been an act of terrorism.
Police said little was known about the unidentified teen, who was shot dead in an exchange of fire with officers after he killed finance worker Curtis Cheng at close range outside the force's headquarters in western Sydney on Friday.
Reports said that the youth, who police said was of Iraqi-Kurdish background and had been born in Iran, had been shouting religious slogans before shooting Cheng in the back of the head.
Turnbull called on Australians to go about their lives as usual as they begin a long weekend in which two major sporting finals will be held in Sydney and Melbourne.
"This appears to have been an act of politically motivated violence so at this stage it appears to have been an act of terrorism. It is a shocking crime," the prime minister said in Melbourne.
"It was a cold-blooded murder, targeting the New South Wales Police Service. It was doubly shocking because it was perpetrated by a 15-year-old boy.
"And it underlines the importance of families, communities, leaders being very aware of whether young people are becoming radicalised," he said.
Andrew Scipione, the police commissioner for the state of New South Wales, of which Sydney is the capital, told reporters that investigators were a "long way" from establishing what exactly prompted the attack, adding that the boy had no criminal history.
Australia has stepped up its efforts in countering the risk of extremist attacks, lifting its terror threat alert to high a year ago, and Scipione said police were aware they could be targeted.
In September 2014, Melbourne police shot dead a "known terror suspect" who stabbed two officers, just one day after the Islamic State group called for Muslims to indiscriminately kill Australians.
And in December of that year, Iranian-born self-styled cleric Man Haron Monis and two hostages were killed following a 17-hour siege at a central Sydney cafe.