An alleged teenage terrorism conspirator who made "explicit threats" to stab Jewish or Assyrian people has been denied bail and deemed an "unacceptable risk" to the community.
The 15-year-old, who cannot be named, was charged on Friday with conspiring to engage in an act in preparation for, or planning, a terrorist act.
A court previously heard the boy claimed to be friends with the 16-year-old accused of stabbing Bishop Mar Mari Emmanuel during a live-streamed sermon in April.
Magistrate James Viney denied the teenager bail on the basis exceptional circumstances did not exist to secure his release.
"There is an unacceptable risk for the protection of the community," he told Parramatta Children's Court on Thursday.
The magistrate said this was of “paramount consideration” and found the boy's alleged explicit threats to stab Jewish or Assyrian people and a previous alleged assault to be "gravely concerning".
The teenager propped his head up with his hand for much of the hearing as he watched on from custody via videolink, as his parents sat in court.
The magistrate said he had "no doubt" the parents were both loving and supportive of their son, and had confiscated his phone after becoming concerned over his behaviour.
"They are genuinely shocked as to the charges he's facing," he said.
After delivering his findings, the boy's mother left the courtroom in tears.
Mr Dib told reporters outside court the parents had been left devastated by the news.
The court previously heard the boy had been involved in an encrypted chat group titled Plans where he talked with co-conspirators who were planning an upcoming attack targeting Jewish or Assyrian people.
Prosecutor Rebekah Rodger said the boys were not just talking and knew people who had acted on threats.
The magistrate detailed messages allegedly sent by the teenager between April 20 and April 21.
"Don’t youse want to do any attack … what about Jews brother what about Palestine? ... I am so cut, I want to do it so bad," the teenager allegedly wrote in one message.
"I really want to do an attack now because I have so much hatred for these kuffar (non-Muslims) its not funny, I want to do jihad now," another message read.
In one exchange, the teenager suggests: "Try not to kill, just stab."
"The messages clearly set out the young person wanted to do something catastrophic," Mr Viney told the court.
The magistrate also expressed concerns over an earlier incident where the teenager was arrested after allegedly throwing a wooden plank towards a worker at a bottle shop and allegedly being in possession of a knife at the time.
The boy’s lawyer Ahmed Dib said his client had a history of behavioural issues, lacked confidence and had low self-esteem.
He said the teenager put on a macho performance in messages about performing an attack but disputed that any such plan was in motion.
Two hand-drawn ISIS flags were found in the boy’s bedroom when police raided the family’s home in April, the court previously heard.
The matter is set to return to court on June 21.