Sri Lanka’s prime minister has said that suspects linked to the Easter Sunday bomb attacks remain at large and could have access to explosives.

Some of the suspects “may go out for a suicide attack”, Prime Minister Ranil Wickremesinghe said in an interview with The Associated Press.

Mr Wickremesinghe spoke frankly about the greatest challenge the South Asian island nation has faced since its civil war ended a decade ago.

“This is another experience for us. Not that we are not strangers to terrorism, but this is global terrorism, so we have to ensure that we root this out,” he said.

Sri Lanka Blasts
A boy lights a candle after the funeral service of Dhami Brandy, 13, who was killed during Easter Sunday’s bomb blast at St. Sebastian Church (Manish Swarup/AP)

Approximately 250 people were killed in the string of suicide bombings at churches and luxury hotels in and around the capital, Colombo, Sri Lanka’s health ministry said. The death toll was revised down from previous police estimates of 359 people.

The attacks were claimed two days later by the Islamic State group, who posted a video of the man Sri Lankan officials say led the attack with seven others.

Police have issued a public appeal for information about three women and two men suspected of involvement in the attacks.

Mr Wickremesinghe also said that the father of two of the suspected suicide bombers, Colombo spice dealer Mohammad Yusuf Ibrahim, has been arrested.

He described him as a leading businessman active in politics known as Ibrahim Hajiar, a Sri Lankan term for Muslims who have gone on religious pilgrimages to Mecca.

The prime minister expressed doubt about Mr Ibrahim’s complicity in the attack.

“People like that would not have wanted their sons to blow themselves up,” he said.

Sri Lanka Church Blasts
Sri Lankan Prime Minister Ranil Wickremesinghe has spoken about the fatal bomb attacks (Eranga Jayawardena/AP)

Sri Lankan authorities have blamed a local extremist group, National Towheed Jamaat, whose leader, alternately named Mohammed Zahran or Zahran Hashmi, became known to Muslim leaders three years ago for his incendiary online speeches.

On Wednesday, junior defence minister Ruwan Wijewardene said the attackers had broken away from National Towheed Jamaat and another group, which he identified only as JMI.

Mr Wijewardene said many of the suicide bombers were highly educated and came from well-to-do families.

The prime minister said it appeared that Sri Lanka’s wealthiest and best-travelled Muslims were most susceptible to the doctrine professed by the Islamic State group.

“They were too educated and therefore, they were misled,” Mr Wickremesinghe said.

The bombers were wealthy enough to have financed the entire operation themselves, though they would have needed outside help for training and bomb-building expertise, Mr Wickremsinghe said.

He said that authorities still had not confirmed whether Zahran, who was supposed to have led one of suicide missions, was among the bodies recovered from the scenes or still at large.

Sri Lanka has been sharply criticised for an apparent intelligence lapse. Government leaders have acknowledged that some intelligence units were aware of possible attacks weeks before the bombings but the president and prime minister both have said the intelligence was not shared with them.

Mr Wickremesinghe blamed the incident, in part, on a “breakdown of communication”.

President Maithripala Sirisena, who was out of the country during the Sunday attacks, had ousted Mr Wickremesinghe in October and dissolved the Cabinet. The Supreme Court later reversed his actions but relations between the two top leaders have remained cold.

In the immediate aftermath of Sunday’s attacks, Sri Lanka blocked most social media, with the prime minister expressing concern that it could be used to incite violence in the country of 21 million.

Mr Wickremesinghe said that security forces were trying to help Muslim Ahmadis from Pakistan seeking refugee status in Sri Lanka, who told AP they had been attacked and beaten in the days following the bombings.

Some people “had become suspicious of foreigners, not of Muslims per se”, Mr Wickremesinghe, said.