COLOMBO, Sri Lanka — Churches, mosques, shops and restaurants were empty in the Sri Lankan capital and elsewhere Sunday as thousands of security forces continued searches, raids and spot checks of vehicles and pedestrians.

The father and two brothers of the suicide bomber who is said to be the mastermind of the Easter attacks were reported killed in a bombing and gun battle with police.

On the first Sunday since the attacks on three churches and on luxury hotels, Catholics watched Mass from home, as Cardinal Malcolm Ranjith, the archbishop of Colombo, broadcast services. He has suspended all Sunday Masses indefinitely in the wake of the Easter blasts.

“Our hearts are tested by the great destruction that took place last Sunday,” Ranjith said. “This is a time that questions such as does God truly love us, does he have compassion toward us can arise.”

Christians are a small minority in Sri Lanka’s multireligious society.

The Mass was attended by President Maithripala Sirisena, Prime Minister Ranil Wickremesinghe and opposition leader Mahinda Rajapaksa, all non-Christians. Rivalries between the three leaders have been blamed for hindering the government from acting on foreign intelligence warnings about possible suicide attacks on churches.

Police said Sunday that 48 people had been arrested in the previous 24 hours in connection with the Easter bombings, which left at least 250 people dead. Among them were two men whose photos had been distributed to the public and who were discovered hiding in a shoemaking shop.

Sirisena decreed that face coverings would be banned in Sri Lanka beginning Monday in what officials described as a security measure to allow authorities to identify people. Senior Muslim officials asked last week that Muslim women remove face-covering niqabs for all security checks.

Police spokesman Ruwan Gunasekara said Sunday a woman who was rescued from the safe house that was at the center of the gun battle and bomb blasts on Friday was Abdul Cader Fathima Kadiyar, the wife of Zahran Hashim, a fanatical Islamist preacher who was identified as the organizer of the attacks and who was killed in one bombing. Police said Hashim’s young daughter also survived. Both women are hospitalized and under police guard. Police said both were identified by Hashim’s driver, who was arrested.

A total of 15 people died in the house in the eastern coastal town of Sainthamaruthu. When police approached the building, they said, occupants responded with gunfire and then exploded several bombs inside. Military officials said the dead included six children.

Authorities said they found detonators, explosive tubing and three identical new backpacks in the house. 

In an undated video that circulated on social media Sunday, three men identified as the father and two brothers of Hashim exhorted others to kill non-Muslims. A brother-in-law of Hashim identified the men in an interview with The Washington Post, and some media reported that all three men had been killed in the safe house conflagration. Local police did not confirm those reports to The Washington Post late Sunday. 

The Easter attacks have been claimed by the Islamic State, but all the individuals who have been identified by authorities as suicide bombers, as well as those who have been detained or sought as suspects, have been Sri Lankan natives. They are said to be affiliated with National Thowheed Jamaath, an extremist Islamist group that has taken root in this multireligious democracy.

In the eastern town of Kattankudy, police on Sunday entered and searched the main mosque of the group, interrupted media interviews with mosque leaders and locked up the building before afternoon prayers, according to the Associated Press. The government formally banned National Thowheed Jamaath and a second Sunni militant group on Saturday, allowing the seizure of property and assets.

The Islamic State, in a statement on its affiliated news agency, claimed that three men who died in the violence in the safe house were its members. It identified the bombers as Abu Hammad, Abu Sufyan and Abu al-Qa’qa. It said they opened fire with automatic weapons and then detonated explosive belts.

In the video on social media, Hashim’s brother Rilwan says in Tamil: “We will destroy these infidel dogs. . . . Our people should prepare for jihad. . . . We will plant our flag and teach a lesson to these infidel dogs who are destroying Muslims.”

Hashim’s brother Zainy urges followers to quit their jobs and join a jihad against nonbelievers.

“Kill them wherever you see them,” he says in the video. “This won’t stop even if we die. You will definitely see these bombs going off everywhere. Don’t give up. . . . Allah will help us. Our brigade will win.”

Rilwan and Hashim, whose home was in the eastern coastal town of Kattankudy, left the area and went into hiding in 2017 after clashing with moderate Muslims there who followed the mystical Sufi strain of Islam. Other family members vanished from Kattankudy just before the bombings, a sister told The Washington Post on Friday. She said Hashim’s extremist views had opened a rift between her and her brother.

Slater reported from Sainthamaruthu and New Delhi. Harshana Thushara Silva and Benislos Thushan in Colombo contributed to this report.