One of the two charges, "acts done in preparation for, or planning, terrorist acts" carries a maximum sentence of life in jail. The teenager was planning on using a homemade explosive device at a public event this week, the police allege. Mr Cartwright, said on Sunday that a number of "improvised explosive devices" were found in the house, which police continued to search on Sunday. "We do believe the young man intended to explode the device at an event over the coming days," he said. "We will allege he was well advanced in preparing a bomb." Despite this, Mr Cartwright said there was no evidence the teenager had planned on attacking a specific event. "At this stage we have no evidence of a specific time or target," he said.

He said police did not expect to make any further arrests over the alleged plot and had not connected any other person to it. Investigators were, however, trying to ascertain if the teenager had been radicalised or recruited online. "Overseas recruiters, and more broadly social media, are a real challenge for us," Mr Cartwright said. "We don't have the answers to countering that, but we work with the broader community to find solutions." The teenager's family were staying elsewhere while police continued to search their two-storey house and were "shocked and surprised" by the terrorism allegations, Mr Cartwright said.

He said the family was "just as much a victim as the rest of the community." Some of the accused's former schoolmates told Fairfax Media on Sunday they were shocked when the boy, who had always been a "good kid", began posting radical views on Facebook late last month. "If you find the act of lashing the fornicator, stoning the adulterer, cutting the hand of the thief unislamic (sic), then know that you've been following some other religion and not Islam," one post read. He wrote in other posts that Shia Muslims were "not human, let alone Muslims," and that Islam was not a religion of peace, but one of justice. One former schoolmate said the accused had always been humble, quiet and softly spoken.

He said that as a Muslim himself, he was offended by the "absurd" things the accused teenager, who cannot be legally named, was posting online.