Five people were arrested in Australia on Wednesday over the fatal terror-linked murder of a police employee, after coordinated raids by more than 200 officers on properties across Sydney.
Those seized in the dawn operation were aged between 16 and 24 and now face questioning over Friday’s shooting of Curtis Cheng.
“Five people have been arrested in relation to the fatal shooting of Curtis Cheng outside police headquarters at Parramatta,” police said in a statement.
Farhad Jabar, 15, shot 58-year-old Cheng in the back of the head outside New South Wales state police headquarters in western Sydney, reportedly shouting religious slogans.
On Tuesday, a student who attended the same school as Jabar was arrested and charged over alleged posts on social media threatening police, with his home searched and two laptops seized.
He was also charged with assaulting and intimidating police and resisting arrest when he was stopped on his way to Arthur Phillip High School in western Sydney on Tuesday.
The 17-year-old, who has not been named, was given strict conditional bail and will face a children’s court on November 9.
Jabar, who authorities said was born in Iran of Iraqi and Kurdish background and had no criminal history prior to the incident, was killed in an exchange of fire with police after shooting Cheng.
Investigators have yet to establish why the police accountant was targeted, although Prime Minister Malcolm Turnbull has said the attack “appears to have been an act of terrorism”.
Authorities on Sunday searched a mosque the teenage shooter is believed to have attended, with the consent of religious leaders.
Canberra is concerned about the prospect of lone-wolf attacks by individuals inspired by groups such as Islamic State, and has cracked down on Australians attempting to travel to conflict zones including Syria and Iraq.
The country lifted its terror threat alert to high a year ago, introduced new national security laws and has conducted several counter-terrorism raids to address the concerns.
In September 2014, Melbourne police shot dead a “known terror suspect” who stabbed two officers, just one day after IS militants called for Muslims to indiscriminately kill Australians.
And in December, Iranian-born self-styled cleric Man Haron Monis and two hostages were killed following a 17-hour siege at a central Sydney cafe.
Australian Justice Minister Michael Keenan said the government was working hard to stop young people becoming influenced by radical extremism.
“We are working to try and divert people if we think they are falling under the spell of ISIL in the Middle East,” he told the Australian Broadcasting Corporation Wednesday, using another name for IS.
“There is a diabolical terrorist outfit that’s taken over parts of Syria and Iraq. Whilst they exist, they will continue to export terror into Australia,” he added.