COLOMBO, Sri Lanka — Sri Lanka’s security forces will conduct a house-to-house search to root out terrorists, the country’s president said on Friday, as the shaken nation grappled with new violence in the aftermath of the Easter Sunday carnage that killed at least 250 people.
President Maithripala Sirisena’s comments, in which he also promised a “total reorganization” of the security apparatus, were seen as tough talk to deflect criticism of the government’s failure to act on repeated warnings about terrorist attacks. But they were also a sign that threat levels remain high across the island nation, and officials have warned that potential suicide bombers could still be planning imminent attacks.
Just hours after the president spoke, security forces conducted at least two raids on the eastern coast, finding explosives and Islamic State flags in one area and facing gun battles and explosions in the other.
“Every household in the country will be checked,” Mr. Sirisena said in a meeting at his official residence with the heads of Sri Lankan media organizations, according to a statement released by his office. “The lists of permanent residents of every house will be established to ensure no unknown persons could live anywhere.”
In a nation of about 22 million people, that would require an enormous effort, and the president’s call brought flashbacks of life during Sri Lanka’s 26-year civil war, which ended in 2009. During those years, the security services maintained a pervasive presence in the capital, Colombo, because of threats of suicide bombings by the separatist Tamil Tigers.
The security services made themselves felt again on Friday as agents, with help from the intelligence agencies and several other countries, continued to search for people linked to the bombings, which they say were committed by a radical Islamist group tied to the Islamic State.
The two raids on the eastern coast occurred about 25 miles south of Batticaloa, where a church was bombed on Sunday, and two days after a large cache of explosives and 25 mobile phones were found after the arrest of a man in that city.
On Friday evening, three explosions went off and a gun battle erupted as security forces raided a suspected bomb workshop in the area of Kalmunai, a city on the eastern coast. The police and miliary “were proceeding in search of a location, said to be producing suicide bomb kits and explosives,” the Sri Lankan Army said in a statement, when five or six people “had begun firing at them.”
In the shootout, two terrorists and one civilian were killed, said Maj. Gen. Aruna Jayasekara, the commander of security forces in the east. Around midnight, security forces still had the area cordoned off and were concerned there might be one or more suicide bombers inside the house, which was in an area populated by civilians, General Jayasekara said.
A few miles away, in or near the town of Samanthurai, the army said, troops searching a house on Friday “recovered ISIS flags, literature and some other objects from a place, said to be the terrorist organization’s place for oath-taking.” Local news media, citing the police, reported that the raid yielded still more explosives, metal balls and a drone camera.
Mr. Sirisena has faced intense criticism since Sunday, when a series of coordinated bombings at churches and hotels killed at least 250 people.
Sri Lankan security officials had written a memo 10 days before the attacks describing the threat of bombings, with names, addresses and phone numbers of those believed to be involved, but the president and prime minister say the warning never reached them. Several of the bombers had been arrested and then released in recent months.
Mr. Sirisena vowed to take action against anyone who had failed to prevent the attack, putting particular blame on two officials: the defense secretary, who resigned on Thursday, and the inspector general of the police, who stepped down on Friday.
“They did not say a word about this warning letter,” Mr. Sirisena said. “It was a serious lapse on their part and shirk of responsibility.”
The Sri Lankan government has been consumed by months of infighting, and Prime Minister Ranil Wickremesinghe, a rival of the president, has complained that he was excluded from security meetings.
Before the bombings, the country’s intelligence forces knew of — and were monitoring — dozens of people in Sri Lanka who had traveled to Syria and joined the Islamic State, and others who had developed radical ties while in other countries, officials have said.
Pressed this week about why such people had been allowed into the country, the prime minister protested that no law in Sri Lanka prevented them from joining or fighting for a terrorist group overseas, or returning home afterward.
But after days of finger-pointing, Mr. Wickremesinghe also apologized in an address to the nation Friday.
“As the prime minister of Sri Lanka, I accept collective government responsibility for the failure to protect people from these attacks. As a government, I extend my sincerest apology to all citizens for our failures,” he said. “I hold myself accountable. And I am committed to ensuring these failures will never happen again.”
[ISIS reminded the world that it does not need to control territory to be a major threat.]
A local Islamist extremist group, National Thowheeth Jama’ath, is said to have carried out the bombings, and some people linked to the plot are still at large, officials said. Images posted online appear to show the Sri Lankans pledging allegiance to the Islamic State, which has claimed responsibility for the attacks, though its exact role is not clear.
Mr. Sirisena said that security forces were making widespread arrests, and that more than 70 people had been held so far. He said he believed there were as many as 140 supporters of the Islamic State in Sri Lanka, according to news reports.
Sunday Masses at Sri Lanka’s Roman Catholic churches were suspended until further notice, the archbishop of Colombo, Malcolm Ranjith, said Friday. Many mosques were not holding Friday prayers.
Hundreds of police officers scoured the capital on Thursday looking for three men and three women who are believed to be connected to the bombers. One suicide bomber tried to strike a hotel on Sunday but could not make his explosive detonate — then blew himself up a short time later, probably while trying to fix it.
A growing number of foreign governments have warned their citizens about increased risks in Sri Lanka. On Friday, Britain advised “against all but essential travel to Sri Lanka,” and the United States ordered the departure of all school-age family members of American government employees there.
In his comments Friday, Mr. Sirisena also said that Zaharan Hashim, the head of National Thowheeth Jama’ath, is believed to have died while carrying out the bombing of a hotel. Mr. Zaharan appeared in a video with seven masked men declaring allegiance to the Islamic State.
Mr. Sirisena said the intelligence failures may have occurred partly because the security agencies had been weakened by the prosecution of military intelligence officers for human rights abuses committed during the civil war.
As he has been cornered politically, Mr. Sirisena has cast himself as a protector of the security apparatus, and accused his opponents of undermining national defense.