Four Singaporeans have been arrested under the city-state’s tough Internal Security Act (ISA) for taking part or intending to join armed groups in the Middle East, the interior ministry said Wednesday.

… “The threat of radicalisation remains a high concern whether online or through some religious leaders,” said terrorism analyst Rohan Gunaratna of the S. Rajaratnam School of International Studies.

“The exposure in military conflict is in itself a cause for concern and such returnees should thoroughly be assessed and guided for reintegration.”