Sri Lankan authorities said an international terror group likely supported an obscure local Islamist group in carrying out a series of bombings on Easter Sunday. Of the 41 Sri Lankan Muslims who traveled to join Islamic State since 2015, only two returned, according to Rohan Gunaratna, of Singapore’s RSIS. Some of those still in Syria, Iraq, or Turkey have helped radicalise Muslims back in Sri Lanka, as well as the Maldives and southern India, and researchers said National Thowheeth Jamath has been a conduit for some of that radicalization.