SYDNEY • A student who attended the same school as a teenager who shot dead a man outside an Australian police headquarters in a suspected terrorist incident has been arrested over alleged posts on social media.
The student was handcuffed and had his belongings emptied on the footpath while on his way to Arthur Phillip High School in western Sydney yesterday, Australian Broadcasting Corporation (ABC) footage showed.
The arrest came after a boy named as Farhad Jabar shot police accountant Curtis Cheng, 58, in the back of the head outside New South Wales state police headquarters in Parramatta last Friday.
ABC said the arrested youth had allegedly praised Farhad on Facebook and posted comments saying the police should "burn in hell".
The Sydney Morning Herald said it had seen a number of posts on the arrested teenager's Facebook account, including one which reportedly said: "Serves you right I hope them lil piggies get shot."
Police, who had a heavy presence at the school which was resuming classes for the first time since the shooting, confirmed the arrest.
"Shortly after 8.3am, police spoke with a teenage boy in relation to alleged posts on social media," New South Wales Police said in a statement. "During the interaction, police allege the teenager threatened and intimidated police."
Farhad, 15, described by the authorities as being born in Iran of Iraqi and Kurdish background with no criminal history prior to the incident, was killed in an exchange of fire with police.
Investigators have yet to establish why the teen gunman targeted Mr Cheng, although Prime Minister Malcolm Turnbull has said the attack "appears to have been an act of terrorism".
The authorities have searched a Parramatta mosque that Farhad was said to have attended with the consent of religious leaders.
Australian officials have said they are concerned about the prospect of lone-wolf attacks by individuals inspired by militant groups such as the Islamic State in Iraq and Syria, and have cracked down on Australians attempting to travel to conflict zones like Syria.
Mr Turnbull yesterday urged Muslim leaders to speak up more against violent extremism.
"Yes they should speak up, but it's more important from a practical point of view that there is leadership in the Muslim community which continues to demonstrate that this type of violent extremism is not consistent with Islam," he said.