SINGAPORE, July 28 -- Three Singaporean teenagers, aged 14 to 19, have been detained under the Internal Security Act (ISA) after they were self-radicalised by violent extremist ideologies and plotted separate attacks within the city-state.

The Internal Security Department (ISD) revealed on July 27 that the cases, while unrelated, highlight a disturbing trend of youth radicalisation.

The detainees were at varying stages of preparation, with some having already identified easily accessible weapons, such as knives, and researching explosive materials online, The Straits Times reported.

The most alarming case involves a 14-year-old Secondary 2 student arrested in May, just a month before he intended to launch a mass stabbing at his school....