Sri Lanka's Catholics awoke Sunday to celebrate Mass in their homes by a televised broadcast as churches across the island nation shut over fears of militant attacks, a week after the Islamic State-claimed Easter suicide bombings killed more than 250 people.

Cardinal Malcolm Ranjith, the archbishop of Colombo, delivered a homily before members of the clergy and the country's leaders in a small chapel at his Colombo residence, an extraordinary measure underlining the fear still gripping this nation of 21 million people.

"This is a time our hearts are tested by the great destruction that took place last Sunday," Ranjith said. "This is a time questions such as, does God truly love us, does He have compassion towards us, can arise in human hearts."

​Show of unity, strength

In a rare show of unity, President Maithripala Sirisena, Prime Minister Ranil Wickremesinghe and opposition leader Mahinda Rajapaksa attended the Mass. Their political rivalry and government dysfunction are blamed for a failure to act upon near-specific information received from foreign intelligence agencies that preceded the bombings that targeted three churches and three luxury hotels.

All Sri Lankan churches were asked to ring bells Sunday while the lamp lighting takes place.

The U.S. Embassy in Colombo has warned against attending any service at a place of worship this weekend.

In the eastern district of Ampara on Sunday, where a gunfight and explosions left 15 people dead the previous day, soldiers guarded St. Mary Magdalen's Church, where a sign on the gate said the church and the school would be closed until May 6. A nearby mosque also had soldiers stationed outside.

At the YMCA, a group of young girls held Sunday school near a portrait of Christ. Sajith Liyanage, a 51-year-old Catholic, said he remained worried and would watch Mass on TV.

"We can't understand what the situation is right now," Liyanage said.

​Country remains on edge

At Ampara's weekly Sunday market, police officers walked explosive-sniffing dogs past ripe-yellow bananas, pineapples and coconuts. Officers also searched women's bags and pushed aside brown fallen leaves, checking the grounds for any bombs.

N.M. Saman Bandarah, a pineapple seller, stood back as the police dog passed. He said he was glad to see the officers but said everyone remained nervous.

"There are no people coming to buy," he said.

Islamic State claims

The Islamic State group, meanwhile, claimed three of the militants who blew themselves up during a police raid in Ampara that was linked to the Easter bombings.

In a statement carried by the extremists' Aamaq news agency, IS identified the bombers by their noms du guerre as Abu Hammad, Abu Sufyan and Abu al-Qa'qa. It said they opened fire with automatic weapons and "after exhausting their ammunition, detonated … their explosive belts."

Sri Lanka's military said the gunfight Friday night near the town of Sammanthurai left 15 dead, including six children, when militants opened fire and set off explosives in suicide bombings as security forces closed in on their safe house.

​Bombs made more lethal

At the main police station in Ampara, an outdoor stage now holds what police recovered after the firefight. The IS-aligned militants had created a bombmaking factory at the home, complete with laboratory-style beakers and thick rubber gloves.

Bags of fertilizer, gunpowder and small ball bearings filled boxes. Police found tens of liters (gallons) of acids, used to make the fire of the blast more lethal.

A police investigator, who spoke to The Associated Press on condition of anonymity as he wasn't authorized to publicly comment, said the mix of acids worsened the wounds suffered by those who didn't immediately die in the blast.

"At the hospital a lot more people died. That's why," he said, nodding toward the acids. "It made the wounds incurable."

The bombers likely carried two rectangular detonators in their pockets similar to the ones recovered, the investigator said. A red switch armed the explosives, while a light teal button detonated the bombs hidden inside of their large backpacks.

Along with the acids, the bombs contained a mixture of fertilizer, gunpowder, ball bearings and explosives typically used by quarries to blast loose rocks, the investigator said. Those explosives made the bombs powerful enough to blow the roof off of St. Sebastian's Church in Negombo, he said, referring to one of the churches near Colombo targeted over Easter.

The Sri Lankan navy controls the sale of the mining explosives and investigators already had begun tracing the serial numbers off of the plastic sticks, he said. A notebook contained bombmaking instructions that had apparently been explained to the writer. (VOA)