PERTH - An 18-year old Australian man has been arrested and charged with collecting documents about how to carry out terrorist acts, police in Sydney said on Tuesday.Sameh Bayda was arrested on Monday evening, and he appeared in criminal court in western Sydney via video link on Tuesday, the Australian Broadcasting Corp. reported.Police had found him in possession of material providing instructions both for stabbing attacks and the use of improvised explosive devices, ABC said, citing documents tabled in court.One of the documents was allegedly published by al Qaeda in the Arabian Peninsula, the ABC reported.Bayda appeared in court via a video-link due to a national holiday. He didn't apply for bail and was formally refused it by the court. He is scheduled to appear again early next month.Australia has been on heightened alert for attacks from home-grown radicals since 2014.Last month a 17-year-old Melbourne man pleaded guilty to a terrorism-related charge after explosives were found at his home. A week earlier two young men were charged with conspiracy to attack government buildings after they were arrested during counter-terrorism raids in Sydney.Police seized a number of items from Bayda's home on January 13 when he was served with a Firearm Prohibition Order, they said in a statement. Under new laws introduced in New South Wales state in late 2013, police can search any person, vehicle or home with this order without seeking a warrant.