One of two 16-year-olds facing terrorism-related charges in Sydney allegedly told his mother he would do “something to them that they have never seen before”, in reference to the murder of NSW Police employee Curtis Cheng in October 2015.

The teenagers were arrested by the state’s Joint Counter-Terrorism Team at Bankstown in Sydney on Wednesday, in the lane behind a Muslim prayer hall.

They were found in possession of two large bayonet-style knives, bought earlier that day, and religious notes that allegedly pledged allegiance to Islamic State.

One of the boys is a relative of Hamdi Alqudsi, who has been jailed for helping young Australians travel to Syria to fight in the country’s civil war.

The pair did not appear in Parramatta Children’s Court on Thursday morning and did not apply for bail, and it was formally refused.

In opposing bail, police said the pair posed an unacceptable risk to the community.

They are due to return to court in December, unless they apply for bail before then.

According to police documents tendered in court, the teen was heard talking to his mother on a lawfully intercepted conversation in October 2015.

During the conversation, he allegedly said:

“When they come, I am going to something to them that they have never seen before. I am going to do something bigger.”

It is alleged the threatened actions were an attempt to draw a “direct comparison” between himself and the murder of police employee Curtis Cheng, who had been shot dead the day before.

Teen ‘tried to travel to terrorist-held region’

Police have alleged the teenager attended a protest four years ago at Hyde Park.

Police said the teenager’s co-accused had shown no remorse for his actions, and while in custody could be seen laughing and joking.

According to the documents, he was stopped by authorities while attempting to enter a region that is controlled by an internationally recognised terror group.

It is also alleged that when he returned to Australia he was found in possession of electronic material believed to have been produced by Islamic State.

– ABC