Sydney - A teenager was on Wednesday charged in Australia with preparing for or planning a terrorist attack after authorities were alerted by social media posts.The 17-year-old boy was detained at his home in Sydney's south late on Tuesday, the latest in a string of arrests by police investigating people suspected of being involved in domestic acts of terrorism."After being alerted to a number of social media posts, police arrested the youth at his home," the New South Wales state police said."He's been charged with one count of acts in preparation for, or planning, a terrorist act... He was also charged with using a telecommunications network with intention to commit a serious offence."The youth was refused bail and is due to appear in a children's court later on Wednesday.Government crack downPolice stressed there was no threat to the community, with his detention unrelated to any previous investigation carried out by counter-terrorism teams.His arrest came as the government announced extra funding for crime-fighting intelligence and surveillance.It included a Aus$1.6 million cash injection to enable better monitoring of social media platforms to reveal threats and thwart radicalisation and recruitment drives.Prime Minister Malcolm Turnbull warned terrorism was "a serious, ever-present threat"."Having said that, we have strong, I believe the best security and intelligence services, we provide them with every support," he added."It is at the very forefront of everything my government does to keep Australians safe."A handful of terror-related attacks have been foiled on home soil over the past 18 months, authorities have said, but several have taken place, including the murder of a Sydney police employee in October.Counter-terror police have made a series of arrests since late 2014, including a 16-year-old boy charged with preparing an attack linked to Anzac Day services honouring Australian soldiers in Sydney in April.Other arrests saw a 17-year-old boy picked up in a raid in Melbourne a year ago, allegedly with "improvised explosive devices" in his family home. More recently, a Sydney-based man was charged last month with planning a terrorist attack, which reportedly involved targeting a naval base close to the city's landmark opera house.The government has become increasingly concerned about homegrown extremism and the terror threat level was raised to high in September 2014. Australia is also worried about its citizens fighting with jihadist organisations such as Islamic State in Iraq and Syria and helping radicalise others, with at least 110 citizens having left to join such groups.