Police have carried out a number of search warrants across Perth today as they continue to track down those responsible for a violent mob attack at City Beach that left several teenagers brutally bashed on Australia Day. Six teenagers, all aged under 18 are now in custody, though no charges have yet been laid. The Australia Day attack, caught on camera, saw three teens taken to hospital with horrific injuries after their heads were stomped on and they were pummelled with punches. The attackers were heard laughing and chanting “BTK”, an initialisation believed to stand for “Born To Kill”. However, police today said they refused to call the attackers a gang, dubbing them “opportunistic, unsophisticated thugs”.