A Sri Lankan soldier stands guard near a car explosion after the police tried to defuse a bomb near St. Anthony's Shrine in Colombo on April 22, 2019, a day after the series of bomb blasts targeting churches and luxury hotels in Sri Lanka.

Militants linked to Easter suicide bombings opened fire and set off explosives during a raid by Sri Lankan security forces on a house in the country's east, leaving behind a grisly discovery Saturday: 15 bodies, including six children.

The gunbattle that began Friday night and the carnage that followed come amid widespread fear of more attacks as officials hunt 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.

Raids and police curfews have shut down areas of eastern Sri Lanka, and Catholic leaders have canceled Sunday Masses indefinitely. Officials also urged Muslims to stay home for prayers in an extraordinary call by the clergy to curtail worship.

The gunfight came after police tipped off soldiers about a suspected safe house near the town of Sammanthurai, where authorities said the militants detonated three explosions and opened fire.

Police spokesman Ruwan Gunasekara said that some of the dead likely were militants who blew themselves up in suicide bombings. Earlier, the military said at least one civilian had been killed in the attack.

A girl and a woman survived the explosion at the suspected safe house but were critically injured and being treated at a nearby hospital, Gunasekara said.

Photographs taken by The Associated Press show the charred remains of one child and the body of another wearing a green T-shirt with the words "good boy" written on the back. The bodies of an adult woman and man were found after the explosion with their clothes burned off.

Meanwhile, the military said security forces had recovered explosives, detonators, "suicide kits," military uniforms and Islamic State group flags in the ongoing raids.

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.

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.

"We don't want repetitions," Ranjith said.

It was an extraordinary request for a Catholic clergyman to make, as churches often remain a refuge. Giovanni Maria Vian, a church historian and emeritus editor of the Vatican newspaper, said he believed it was the first time the church had canceled Masses across a country for security reasons.

In Galle Face, a normally crowded ocean side park in Colombo near some of the hotels that were bombed, only a few people could be seen Saturday. Kiosks were closed, and traffic was lighter than usual, with security officials blocking streets and checking vehicles at barricades.

Yashwant Kumar Singh, 23, a worker from India, said he wants to go back to his homeland because he fears another attack. "If it only happened on one day, then that wouldn't have been so difficult, but bombs are going off here every day. That is why there is an atmosphere of fear. We are feeling very scared."

Business was also being hurt.

"All of Colombo city is too empty," said Diluka Gayashan, standing outside the juice bar where he works. "That's the problem. And now the government is enforcing a curfew from 10 at night until early in the morning, 4 or 5. It's not good."

On Saturday, cleaning crews arrived to St. Anthony's Shrine in Colombo, where broken glass still littered a blood-stained floor. They collected debris, tossing it into a truck parked outside as a heavy contingent of security forces stood guard.

The U.S. Embassy in Sri Lanka has warned the public to stay away from places of worship over the weekend, a stark alert underlining that authorities believe that attackers remain at large.

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. At a mosque in Colombo, police armed with Kalashnikov assault rifles stood guard outside for hundreds of worshippers.

The Easter attackers are "not Muslims. This is not Islam. This is an animal," said Akurana Muhandramlage Jamaldeen Mohamed Jayfer, the chairman of the mosque. "We don't have a word (strong enough) to curse them."