As the death toll following Sunday’s terror attacks targeting Sri Lanka’s churches and luxury hotels rose to almost 300 on Monday, government officials pointed the finger at an unknown radical Muslim group – the National Thowheed Jamath.

The government is yet to release a statement regarding who carried out the terror attacks, but ministers and officials believe that an extremist group is behind the bombings.

On Sunday, telecommunication minister Harin Fernando released an intelligence report on social media, and blamed the government for not taking action sooner.

The three-page document outlines details of “alleged planned attacks” by a group called the National Thowheed Jamath (NTJ) and was sent by the Ministry of Defence to the inspector general of police 10 days ago.

The report chronicles the names of four suspects – one of whom is believed to have died in the eighth and final explosion on Sunday as police raided a residence in the Dematagoda suburb of Colombo.

Sri Lanka: Scene of the bomb attacks and aftermath Show all 38 1 /38 Sri Lanka: Scene of the bomb attacks and aftermath Sri Lanka: Scene of the bomb attacks and aftermath Sri Lankan Special Task Force officers raid a house following an explosion in capital Colombo AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath A blood-spattered statue of Jesus Christ while crime scene officials inspect the site of a bomb blast, as the sun shines through the blown-out roof, inside St Sebastian's Church in Negombo Reuters Sri Lanka: Scene of the bomb attacks and aftermath A police officer inspects the damage after a bombing at the Shangri-La Hotel in Sri Lankan capital Colombo AP Sri Lanka: Scene of the bomb attacks and aftermath Sri Lankan soldiers look on inside the St Sebastian's Church at Katuwapitiya in Negombo following a bomb blast during the Easter service AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath A woman cries next to a coffin of a bomb blast victim. A series of eight devastating bomb blasts ripped through high-end hotels and churches holding Easter services in Sri Lanka on April 21, killing more than 300 people AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath People who live near the church that was attacked the day before, leave their houses as the military try to defuse a suspected van before it exploded in Colombo Reuters Sri Lanka: Scene of the bomb attacks and aftermath Shoes and belongings of victims are collected as evidence at St Sebastian's Church AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath Sri Lankan police were forded to clear an area while Special Task Force Bomb Squad officers inspected the site of an exploded van near a church the day after it was attacked Reuters Sri Lanka: Scene of the bomb attacks and aftermath The Kingsbury Hotel in Colombo, Sri Lanka following a bombing AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath Queues at the National Blood Bank in Colombo, Sri Lanka after a request for blood to aid in recovery efforts Mr Lavasquabble/Twitter Sri Lanka: Scene of the bomb attacks and aftermath Medical response team work to remove dead bodies from the scene of bombings in Sri Lankan capital Colombo AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath Sri Lankan security personnel inspect the debris of a car after it exploded when police tried to defuse a bomb AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath Security personnel work at the scene of a bombing at a church in Batticaloa in Sri Lanka AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath A woman is helped near St Anthony's Shrine after a blast in Colombo, Sri Lanka, on Sunday 21 April 2019. At least 130 people were killed and more than 500 hospitalised after near-simultaneous explosions hit three hotels and three churches on Easter Sunday. AP Sri Lanka: Scene of the bomb attacks and aftermath Sri Lankan police officers clear the road as an ambulance drives through carrying injured of church blasts in Colombo, Sri Lanka, on Sunday 21 April 2019 AP Sri Lanka: Scene of the bomb attacks and aftermath A Sri Lankan soldier stands guard near a car explosion AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath A woman prays at St. Sebastian's Church in Negombo AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath Priests stand inside St Anthony's Shrine, Kochchikade church on the outskirts of Colombo after a bombing Reuters Sri Lanka: Scene of the bomb attacks and aftermath A Sri Lankan woman living near St. Anthony's shrine runs for safety with her infant after police found explosive devices in a parked vehicle in Colombo AP Sri Lanka: Scene of the bomb attacks and aftermath People react during a mass for victims, two days after a string of suicide bomb attacks on churches and luxury hotels Reuters Sri Lanka: Scene of the bomb attacks and aftermath Security personal react as a device was detonated in a controled explosion in a van near the St Anthony's Church EPA Sri Lanka: Scene of the bomb attacks and aftermath Security forces inspect the scene of a bombing at the Shangri-La Hotel in Sri Lankan capital Colombo Getty Sri Lanka: Scene of the bomb attacks and aftermath The Kingsbury hotel in Colombo, Sri Lanka after a bombing attack Getty Sri Lanka: Scene of the bomb attacks and aftermath The damaged interior of a church in Negombo, Sri Lanka following a bombing attack Reuters Sri Lanka: Scene of the bomb attacks and aftermath Police and security personnel stand guard outside the Shangri-La Hotel in Sri Lankan capital Colombo following a bombing attack EPA Sri Lanka: Scene of the bomb attacks and aftermath Debris is seen at St Anthony's Church in this still image from video footage after explosions hit churches and hotels in Colombo, Sri Lanka, on 21 April 2019 Derana TV/via Reuters Sri Lanka: Scene of the bomb attacks and aftermath Damage inside a church following a bombing attack AP Sri Lanka: Scene of the bomb attacks and aftermath A Sri Lankan Special Task Force officer scales a house during a raid following an explosion in capital Colombo AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath A general interior view showing damage after an explosion hit St Anthony's Church in Kochchikade, Colombo, Sri Lanka, on Sunday 21 April 2019 EPA Sri Lanka: Scene of the bomb attacks and aftermath Priests walk into St Anthony's Shrine Kochchikade church after an explosion in Colombo, Sri Lanka, on 21 April 2019 Reuters Sri Lanka: Scene of the bomb attacks and aftermath A Sri Lankan police officer stands outside St Anthony's Shrine in Colombo, Sri Lanka, after a blast on Sunday 21 April 2019 AP Sri Lanka: Scene of the bomb attacks and aftermath A shoe of a victim is seen in front of the St Anthony's Shrine, Kochchikade Church Reuters Sri Lanka: Scene of the bomb attacks and aftermath Local and security officials gather at the scene at St Anthony's Church in Kochchikade, Colombo, Sri Lanka EPA Sri Lanka: Scene of the bomb attacks and aftermath An ambulance is seen outside the church premises with gathered security personnel following a blast at St Anthony's Shrine in Kochchikade, Colombo, on Sunday 21 April 2019 AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath Armed policemen patrol the area after an explosion hit at St Anthony's Church in Kochchikade in Colombo, Sri Lanka, 21 April 2019 EPA Sri Lanka: Scene of the bomb attacks and aftermath Sri Lankan Army soldiers secure the area around St. Anthony's Shrine after a blast in Colombo, Sri Lanka, Sunday 21 April 2019 AP Sri Lanka: Scene of the bomb attacks and aftermath Sri Lankan security personnel keep watch outside the church premises following a blast at the St Anthony's Shrine in Kochchikade, Colombo, on Sunday 21 April 2019 AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath Police officers inspect the scene after an explosion hit at St Anthony's Church in Kochchikade in Colombo, Sri Lanka, 21 April 2019 EPA

“According to international intelligence, members of the National Thowheed Jamath have planned to attack prominent churches and the Indian High Commission in Sri Lanka,” reads the document.

Very little is known about NTJ, although the intelligence report states that a member named Rilwan was involved in the desecration of a number of Buddhist statues in Mawanella, central Sri Lanka last December. The incident led to a flare-up in tension between Buddhist and Muslim communities.

In the police document, it is said that Rilwan went into hiding following that incident. He is also identified as the brother of a man named Zahran Hashim, identified as the suspected leader of NTJ.

Such is the obscurity of NTJ that many government officials said they were unaware of its existence. ABM Ashraf, director of the Muslim Affairs ministry, told The Independent: “We had never heard of this terrorist organisation until yesterday.”

Their social media presence is sparse, too. Although they appear to have a Facebook page, it has only been updated once every few weeks or so. Their Twitter page hasn’t been updated since March 2018.

Several government ministers said that Sunday’s terror attacks – the worst since the country’s 30-year ethnic war – could have been avoided if the government had been more responsible.

“We regret the fact the knowledge regarding the impending attacks on churches which was made available through intelligence agencies was not relayed to the archbishop. Which if done in time, could have prevented this mayhem,” said Rauff Hakeem, urban development minister, referring to the warning about the alleged National Thowheed Jamath report.

“As a community we are outraged,” said Hakeem, who belongs to the Muslim minority that makes up just 10 per cent of the island’s population. “The strongest punishment possible should be given to these perpetrators,” he said.

Hakeem also stated that the perpetrators “couldn’t have been home grown” as the attacks “were done in such sophisticated coordination”.

Fernando also believes the hitherto unknown radical group is responsible for the attacks and says the government “should have taken the allegations more seriously”.

“This is a minority extremist group which obviously doesn’t believe in the Islamic faith, which is peaceful and practised by our wider community of Muslims,” said Fernando.

“It is a very, very small faction of the Muslim community who are in no way representative of the Muslims of our country,” he added.

Officials of the Jamiyyathul Ulama, the umbrella organisation of Muslim bodies in Sri Lanka, say they have been monitoring a rise in radical movements among the Muslim community, and reporting the issue to the government and security services.

According to the organisation, Sri Lanka was the first country to make a statement condemning Isis in 2014, saying that the extremist group’s doctrines do not belong to Islam.

“Unfortunately after Isis some youngsters became attracted to the idea ... And in the past two years we have noticed some [radical] behaviours on social media,” Sheikh Akram Noor Ramith, secretary for youth affairs of Jamiyyathul​, told The Independent.

“We strongly believe that there is an international hand behind Sunday’s attacks,” he said.

Officials say 24 suspects are in custody and the operation to crack down on the cell behind the suicide bombings continues.

A police cordon remained at the three-storey house of a well-respected Muslim spice dealer in Dematagoda, a suburb of Colombo, where the eighth bombing took place on Sunday, and police were seen carrying firearms out of the building on Monday afternoon.

Two explosions, both from the same house, rocked the quiet and affluent residential area as police entered the home on the back of a tip-off from the public. The roof of the house caved in as the two bombs exploded on the top floor, killing three policemen and several members of the family.

Sources at the scene told The Independent that the bodies of two children were carried out on Sunday. “We believe there was a third child in the house, and are certain there are more bodies under the debris,” said an official.

A little way up the street, a young woman living in a two storey house climbed into a police jeep as she was taken into custody on Monday. The police taking the woman into custody refused to comment.

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“We are shocked,” says Aravindi Kaushalya, a neighbour who lives three houses away from the scene of crime. “We have lived here for over 40 years, and that family has lived just across us for the past 20 years. Who would have thought they had guns and bombs in their house?” she asked.

However neighbours also said the family kept to themselves. “We know some of our Muslim neighbours well, but this particular family kept away from all of us.”