The path from Sri Lanka to Syria is not a well-trodden one. It is thought that only several dozen Sri Lankan Muslims travelled to the Middle East to join Islamic State.
The number is far lower than most other surrounding South Asian countries, which have had a large number of their nationals make the journey.
The Sri Lankan government warned in 2016 that 32 Muslims from four “well-educated and elite” families had already gone to Syria.
According to Jihad Watch, scores of them returned to Sri Lanka later that same year.
It is not clear what happened to them, but it has been reported that a number were among those arrested by Sri Lankan authorities in connection with the Easter Sunday bombings, as well as one Syrian national.
It raises the possibility that the attackers could have either been returnees or at least had organisational links to Isil.
Two of the hotel bombers were on Tuesday reported to have been the sons of a “wealthy” Colombo spice trader.
They blew themselves up as guests queued for breakfast at the Shangri-La and Cinnamon Grand hotels in the capital, a source told AFP.
The pair were key members of the Islamist National Thowheeth Jama'ath (NTJ), which the government has previously blamed for defacing Buddhist statues.
The NTJ is an offshoot of the Tauhid Jamaa’at in India’s southern Tamil Nadu state, which has been active for several years in organising blood donation camps, anti-alcohol temperance marches and protests against films deemed offensive to Islam.
Moulvi Zahran Hashim, a prolific imam with NTJ also professed his support for Isil in videos released on his social media channels.
NTJ was first the Sri Lankan intelligence radar after some 100kg of military-grade explosive material and 100 detonators were seized at a remote farm in Wanathawilluwa on the islands west coast earlier this year.
Experts suggested that the group would have had to have help from an international group to carry out such a sophisticated, complex attack.
Since Isil lost all the territory it once held across Iraq and Syria last month, there's been more concern among nations about foreign fighters returning home.
"There weren't many (Sri Lanks who joined Isil), but there don't have to be many," said Robert Pape, a political science professor at the University of Chicago who directs the school's Chicago Project on Security and Threats.