No individual or group has made a formal claim of responsibility as of Monday morning for the horrific Easter Sunday bombings in Sri Lanka, which killed almost 300 people at the latest count, but the Sri Lankan government considers a radical Islamist group called National Towheeth Jamath (NTJ) and its leader, Imam Moulvi Zahran Hashim, the prime suspects.

Sri Lankan Health Minister Rajitha Senaratne described the group on Monday as an “international network without which these attacks could not have succeeded.”

“There had been several warnings from foreign intelligence agencies about the impending attacks. Persons named in intelligence reports are among those arrested. Some named in the reports had died during attacks,” Senaratne said.

“We don’t see how a small organization can do all of this. We are now investigating international support for the group and their other links,” he said.

Senaratne said the Sri Lankan government received “several warnings from foreign intelligence agencies about the impending attacks.” At least one of these warnings was a document that explicitly named the NTJ and said they planned to attack churches.

Other officials were equally insistent the bombers had assistance from foreign terrorist organizations. Sri Lankan authorities have made 24 arrests so far in the course of investigating the attacks.

NTJ, whose name is sometimes rendered in English as “National Thowheed Jamath,” is a previously obscure extremist group that split off from an Islamist organization called Sri Lanka Towheeth Jamath (SLTJ) several years ago.

The precise timing and degree of the separation is somewhat murky, in part because NTJ keeps a surprisingly low profile for an extremist organization in the Information Age. The BBC noted on Monday that NTJ only updates its Facebook page once every few weeks, has not issued a tweet since March 2018, and appears to have taken its website offline.

Indian Express reported the Sri Lanka Towheeth Jamath is taking pains to distance itself from NTJ, condemning the Easter Sunday attacks and calling for “the highest punishment to the perpetrators.” The SLTJ organized a blood drive for victims of the attacks on Sunday and used its Facebook page to offer further assistance.

Asia Times reported some infighting between Sri Lankan officials due to allegations that “the prime minister and Cabinet were not informed about an intelligence warning from Indian officials of possible attacks because of the bitter rift between the PM and the President, as the latter oversees national security.”

Asia Times quoted Indian security sources speculating that “rogue elements within the Pakistani intelligence [service]” might have been involved in the bombing plot, and that some Sri Lankan and Maldivian extremists have “trained in Afghanistan along with the IS-Khorasan Province, an affiliate of the main Syria-based Islamic State.”

One India reported on Sunday that several dozen Muslims from upper-class Sri Lankan families are known to have joined the Islamic State and returned from Syria after the collapse of the “caliphate.” At least one Sri Lankan ISIS recruit has been accused of plotting a terrorist attack in Australia. The police believe ISIS has attempted to smuggle explosives into Sri Lanka.

The warning document police issued this month named Moulvi Zahran Hashim as the spiritual leader of the NTJ. The Jerusalem Post on Monday described his “history of racism and Islamic supremacy”:

In July 2017, for example, Sri Lanka press reported that the organization’s leaders were being prosecuted for making derogatory remarks in a video against Buddha and hurting the sentiments of the Sinhala-Buddhist community in the country. Hashim has likewise posted several YouTube videos during which he preaches comments that could be considered incitement. “For years, the faithful man spread his incitement without being banned,” he describes on his video. In another one, he says: “What can Sri Lankan Muslims do for Dr. Zakir Naik?” Naik is the president of the Islamic Research Foundation in India and is considered to preach incitement and support terrorism.

According to the Jerusalem Post, journalists on the left have “pushed back against the reports, accusing the press of being ‘Islamophobic’ for reporting his name.”