Jameel Mohammed Abdul Latheef was identified by authorities as one of the bombers. The bombings at hotels and churches in and around Colombo on April 21 left hundreds dead and hundreds more wounded.
Latheef also met with Neil Prakash, an Australian citizen and ISIS recruiter.
Latheef, who studied in both the UK and Australia, eventually earning a degree in aeronautical engineering, is believed to have trained with ISIS for three to six months, the source said. He was then sent to Sri Lanka, his home country, to serve as a recruiter before helping carry out the attacks.
Up to three of the other bombers are also being investigated for travels to Turkey, Syria, or Iraq, a source told the Journal.
Like many of the bombers, Latheef grew up comfortably and received an education after being born the sixth child in a tea trading family, sources told Reuters. The family’s wealth enabled him to study abroad. He was married around 2007 and had four children.
Friends said that around the time he moved to Australia for four years in 2009, he became radicalized.
A Sri Lankan intelligence source said that Latheef did try to travel to Syria in 2014 with a friend, but turned back once he got to Turkey. The friend joined ISIS in Syria.
At one point in the clip, al-Baghdadi is heard praising the Sri Lanka terrorist attackers.
Sources told the Journal that Sri Lankan intelligence officials found the Sri Lanka bombers used encrypted messaging applications Telegram and Threema to communicate with their contacts inside ISIS. While the Thoweek group was named publicly as being behind the attack, another local Islamist group, Jammiyathul Millathu Ibrahim, is also believed to have been involved.
“Their ideology is very close to ISIS. It is totally a terrorist organization,” a senior security official told the Journal about the group. “They believe in violence only. They are highly motivated top-class people.”