Tan was one of three male teenagers detained under the Internal Security Act<\/span><\/a> between April and June. The other two, aged 14 and 15, were not named because of their ages.<\/p>\nAlthough unrelated to one another, they had been self-radicalised online and planned to carry out attacks in Singapore.<\/p>\n
Tan, who converted to Islam in early 2022 after learning about the religion on social media, was exposed to radical foreign preachers later that year.<\/p>\n
By January 2025, he was consuming pro-ISIS material online and eventually concluded that \u201carmed violence was permissible against kuffar<\/i> (disbelievers)\u201d, ISD said.<\/p>\n
Besides non-Muslims, Tan also considered Shi\u2019ite Muslims, Muslims whose religious views differ from his own, and those who serve secular governments, to be part of this group.<\/p>\n
Before he devised physical plans for violence, Tan attempted cyber attacks in mid-2025, targeting the websites of several local and foreign Muslim organisations that he deemed to be deviant.<\/p>\n
These included the Muhammadiyah Association (Singapore), Jaafari Muslim Association Singapore and a foreign organisation associated with the Ahmadiyya sect.<\/p>\n
Using malware that he downloaded, he carried out distributed denial-of-service (DDoS) attacks on these websites, with the aim of flooding their servers with internet traffic to prevent users from accessing them.<\/p>\n
ISD said Tan wanted to do so to \u201cprotect Muslims from what he believed to be misguided teachings\u201d.<\/p>\n
Although he recorded himself justifying his actions, he did not disseminate the oral declaration as he was unsure if his attacks succeeded, given that the websites remained accessible.<\/p>\n
The police are separately investigating Tan for potential offences under the Computer Misuse Act.<\/p>\n
At the end of 2025, he devised plans to target both SAF personnel and LGBTQ students at the tertiary institution he attended, and was prepared to be killed in the process of carrying them out.<\/p>\n
He regarded the SAF service members as \u201cenemy combatants serving the \u2018kuffar Government\u2019 of Singapore\u201d, and prioritised them as targets, believing that killing them would earn him greater divine rewards and increase his chances of dying a martyr.<\/p>\n
He also targeted his LGBTQ peers because he viewed their behaviour as not conforming to the teachings of Islam.<\/p>\n
To prepare for the attacks, he researched knife skills online and planned to buy a knife with a 10cm blade from a hardware store in a shopping mall.<\/p>\n
ISD noted that Tan had no specific timeline for his domestic attacks. Instead, he intended to use them as a back-up plan if he was unable to travel overseas to participate in armed jihad \u2013 a path he believed would guarantee his martyrdom if he died in battle.<\/p>\n