As Sri Lankan security forces raided an ISIS safe house late Friday into Saturday morning, militants open fired and detonated at least three suicide bombs, killing 15 people, including six children. The dead were found charred, others had their clothes burned off of their bodies.

Police tipped off soldiers about a suspected safe house in the town of Sammanthurai as part of a widespread search operation for militants with explosives believed to still be at large after the coordinated bombings of churches and luxury hotels that killed more than 250 nearly a week ago.

US RAISES TRAVEL WARNING AFTER SRI LANKA SUICIDE BOMBINGS

The military also issued curfews for civilians, and Roman Catholic churches have canceled Masses indefinitely. Authorities told Muslims to worship at home rather than attend communal Friday prayers that are the most important religious service of the week, but several mosques held services anyway.

Police spokesman Ruwan Gunasekara said that some of the dead found at the safe house were militants who blew themselves up. Earlier, the military said at least one civilian had been killed in the attack. At least two people, a woman and a girl, survived the gunbattle and bombing episode and were being treated at a hospital for serious injuries.

During the sweeping raids, military officials said security forces discovered explosives, detonators, "suicide kits," military uniforms and Islamic State group flags. It was not clear whether these items were found at the same safe house or elsewhere.

Gunasekara said officers acting on information from intelligence officials also found 150 sticks of blasting gelatin and 100,000 small metal balls, as well as a van and clothing suspected of being used by those involved in the Easter attacks. Suicide bomb vests often are packed with such balls to increase the shrapnel in the explosion, making them even deadlier.

Fear of more attacks has led to increased security at shrines, churches, temples and mosques across the multiethnic country of 21 million off the southern coast of India.

Sri Lanka's government, crippled from a long political crisis between the president and prime minister last year, promised swift action to capture militants still at large. President Maithripala Sirisena said about 140 people had been identified as having links to the Islamic State group.

A "major search operation has been undertaken," Sirisena said. "Every household in the country will be checked."

Cardinal Malcolm Ranjith told reporters Friday that church officials had seen a leaked security document describing Roman Catholic churches and other denominations as a major target. Ranjith, who is the archbishop of Colombo, asked the faithful across Sri Lanka to stay home for their own safety.

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On Friday, police confirmed the militant group's leader, Mohamed Zahran, died in the suicide bombing at the Shangri-La Hotel, one of six hotels and churches attacked. Zahran appeared in an Islamic State video claiming responsibility for the coordinated assault, and authorities in both Sri Lanka and Australia confirmed links between IS and the attack.

On Thursday night, Sri Lanka's Health Ministry drastically reduced its estimated death toll from the bombings. A statement said "approximately" 253 people had been killed, nearly one-third lower than an earlier police estimate of 359 dead.

The Associated Press contributed to this report.