One of two teenagers arrested with bayonets in Sydney’s south-west has been found guilty of planning a terror attack.

The boy did not react as the unanimous verdict was delivered after four days of deliberations.

The jury is still deliberating on a verdict for his co-accused who also can’t be identified.

They were aged just 16 when they were arrested at a Bankstown prayer hall in 2016, shortly after the bayonets were bought.

Although the Crown couldn’t say when they boys planned to carry out the attack and on whom, they alleged they were in possession of a half-written note pledging allegiance to Islamic State.

They also tendered CCTV of the friends buying two other knives almost a week earlier and images downloaded to their phones.

The teenager found guilty was accused of holding extremist views for many years.

He had been photographed as he held up a sign at the Hyde Park riots when he was aged just 12.

The placard read “behead all those who insult the prophet”.

He had also refused to stand up for the Australian national anthem at a school assembly.

“I will only stand up for Allah and I do not respect the Australian Government because they sent troops overseas to kill the men and rape the children” he allegedly told his principal.

The day before the arrest one of the boys allegedly looked up an image online which had the words “I am a warrior of Islam and my path is Jihad”.

His barrister told the jury to ask themselves whether he was anything more than a young, enthusiastic and curious Muslim.

Both pleaded not guilty to doing an act in preparation for a terrorist attack.