The country’s real divide has been between Buddhists and Muslims, but the Easter attacks may change all that.

In November 2016, Sri Lanka’s justice minister announced to Parliament that 32 locals from four families had joined the Islamic State. Given the minister’s ties to some anti-Muslim Buddhist prelates, his claim was quickly dismissed as opportunistic—even racist. Since then, however, credible evidence has backed him up. Meanwhile, the Islamic State has claimed responsibility for the deadly Easter Sunday bombings that killed around 360 people, including nearly 40 foreigners.

To be sure, the Islamic State has a reputation for taking credit for terrorist acts it had nothing to do with. Its claims must therefore be treated skeptically. At the same time, however, there is no gainsaying that Islamist terrorist groups in South Asia and elsewhere support the Islamic State’s vision for a caliphate and crave alliance with it. And these groups, in solidarity with the Islamic State, have in the past targeted Christians on Easter. One such group is Jamaat-ul-Ahrar, which killed 75 people in Lahore, Pakistan, in March 2016.

Yet the specifics of the Sri Lankan case make it unusual. For one, given the planning, sophistication, and scale, the attacks there on April 21 rank as one of the worst terrorist acts recorded. But more importantly, the relationship among the country’s Buddhists, Christians, and Muslims makes the targets the attackers picked somewhat strange. After all, why would the Islamic State or those allied with it go after the Christian minority when it is the radical Sinhalese Buddhist nationalists who have perpetrated violence against the island’s Muslims in recent times?

The histories of Sri Lanka’s ethno-religious groups only add to the puzzle. In 2009, the country’s decades-long civil war ended with the defeat of the Liberation Tigers of Tamil Eelam (LTTE). During the violence, the LTTE often resorted to suicide bombings, and it is understandable that people initially thought the group was responsible for the weekend attacks. Although the Sri Lankan military has feared an LTTE comeback, though, the now defanged group never really mounted such coordinated bombings even at the height of its military power. In any case, the LTTE never attacked Christians if only because many Tamil Christians played a leading role in the separatist struggle.

Meanwhile, extremist Buddhists have periodically attacked Christian evangelical groups, but suicide bombings are not really their forte.

This left Islamist extremists as the potential culprits, yet Muslims in Sri Lanka have never before resorted to suicide bombings, and their moderate leaders have gone to great lengths to discourage reprisals for anti-Muslim attacks.

The two local Islamist groups that the government claims were involved in the bombings are relatively obscure. One is Jammiyathul Millathu Ibrahim (JMI), of which little is known. The other is National Thowheed Jamath (NTJ), which appears to have been set up after Sinhalese Buddhist radicals with links to the previous Mahinda Rajapaksa regime orchestrated a wave of anti-Muslim violence in June 2014. There exist various jamath organizations in Sri Lanka and South Asia thanks to breakaway factions. The NTJ could well be one such breakaway faction.

The NTJ gained some notoriety when one of the Easter suicide bombers desecrated a Buddha statue last December. It is unlikely someone intent on participating in coordinated suicide attacks would have wanted to expose himself by resorting to such an inflammatory act, so last weekend’s attacks must have been planned recently.

The NTJ is surely linked to the Tamil Nadu Thowheed Jamath, whose puritanical demands have caused it to clash with Islamist groups in the south Indian state. The NTJ has likewise upset moderate Sri Lankan Muslims for its ambitions to impose a Wahabi lifestyle on the island’s Muslims within its reach. But no one appears to have thought the group was capable of unleashing the carnage it did this past Sunday.

Muslims amount to less than 10 percent of Sri Lanka’s population, and JMI and NTJ followers are unlikely to account for even 2 percent of those. Their miniscule size, coupled with the sophisticated nature of the attacks and the targeting of churches rather than Buddhist temples and assemblies, was therefore one reason for concluding a foreign hand was involved.

Now pro-Islamic State posts on social media claim that the attacks were a response to the Christchurch, New Zealand, mosque shootings that killed 50 Muslims. The Sri Lankan government has also concluded that the Christchurch shootings were what inspired the attack. But the murder of Muslim worshippers in New Zealand had nothing to do with Sri Lanka or Sri Lankans. So why was the country chosen?

Appreciating the Islamic State worldview, which is rooted in a binary of “believers” versus “infidels,” may help in this regard. The group envisions a permanent war between believers who defend Islam and crusaders who undermine the religion in varied ways, including those whose lifestyles are antithetical to fundamental Islamic values. Their worldview respects no borders and nationalities. As far as the Islamic State and its affiliates are concerned, then, Sri Lankan Christians fit into the crusader bracket and qualify to being attacked.