A teenager was arrested by the New South Wales Police in northwestern Sydney on Tuesday morning for allegedly plotting an “imminent” terrorist attack.

Tamim Khaja, who is believed to be a former student at Epping Boys High School, was caught by authorities at Macquarie Park.

Australian Federal Police Acting Deputy Commissioner Neil Gaughan said that the police will assert that the 18-year-old was looking to get a firearm and search for potential sites in Sydney where he could conduct a terrorist attack.

NSW Police Deputy Commissioner Catherine Burn revealed that the teenager seems to have “associations with some people who have been put before the courts.”

However, she did not provide any information as to who these people are and how they are connected. She stressed that the suspect acted alone on the alleged terrorist plot, according to ABC News.

Burn also said in a news conference that Khaja has been allegedly planning to leave the country and join the Islamic State in Syria.

Back in February, the teenager was intercepted by police authorities at Sydney Airport, and his passport was cancelled as a result, according to News.com.au.

Police clarified that the arrest was not related to Operation Middleham, through which counter-terrorism officers for the state of Victoria raided numerous homes in Melbourne earlier this morning.

Khaja is not the only teenager who has been arrested for planning an alleged imminent terrorist attack, as another teenager was also arrested a day before this year’s Anzac Day services and events.

The 16-year-old who was not named due to legal reasons was denied bail. His lawyer Zemarai Khatiz presented a not guilty plea on his behalf before the Parramatta Children’s Court.

Khatiz mentioned at the time that he would be producing supporting evidence based on a report from a psychologist.