President Abdel Fatah al-Sissi said Monday that a suicide bomber was responsible for an attack that killed 24 worshipers at Cairo’s Coptic cathedral complex during Sunday Mass, as outrage grew among Egypt’s Christian minority.

Speaking to hundreds of mourners at a state funeral, Sissi said that the bomber wore a vest packed with explosives and that four people suspected of aiding him had been arrested. Security forces were looking for two people with possible links to the attack, he said.

The country’s Interior Ministry described the bomber as a 22-year-old man from the town of Fayoum, 60 miles south of the capital, Cairo. It also released a picture of what it said was the bomber’s head.

At least 49 people were wounded in the explosion at the Botrosiya Church, which is also known as the Church of St. Peter and St. Paul. The church is adjacent to St. Mark’s Coptic Orthodox Cathedral, the seat of the Coptic pope, Tawadros II.

The attack was the deadliest on Christians since a suicide bomber killed 23 congregants at a church in Alexandria on Jan. 1, 2011.

Health Ministry officials lowered the death toll by one, to 24, suggesting that the bomber had initially been counted among the victims. Many of the dead were women and children.

No group has asserted responsibility for the bombing, and Sissi did not name any suspected organizations as being involved. But the attack bore the hallmarks of Islamic extremists — including Egypt’s Islamic State affiliate — who have been behind numerous attacks on soldiers, police and government officials, as well as Christians, across the country this year.

“The attack brought us great pain, but we will never be torn apart,” Sissi told the mourners. “God willing, we will win this war.”

Sissi, along with Pope Tawadros, led a procession in which soldiers carried the victims’ coffins, draped in the national flag, to the state funeral. Earlier, a service was held at the Virgin Mary and St. Athanasius Church in Cairo.

After praying over the coffins, Tawadros sought to defuse the mounting anger among Christians, who make up 10 percent of the population. The community has long felt discriminated against by the country’s Muslims and successive authoritarian governments.

Attacks against Christians have spiked since the 2011 populist revolution that ousted President Hosni Mubarak, and especially after the military overthrew an elected Islamist government in 2013.

After the bombing Sunday, a crowd of Christians outside the cathedral angrily denounced the police and the government for not protecting them.

“This calamity is not against the church but against the homeland, against all of Egypt,” Tawadros told the mourners. “Those who commit acts such as this do not belong to Egypt at all, even if they are on its land.”

On Monday, Sissi called for stricter anti-terrorism laws but dismissed public accusations that Egypt’s security forces had not adequately protected the church.

Human rights activists urged the government to conduct a proper investigation of the bombing and to protect the Christian community as the holiday season approaches.

“Egypt’s government needs to ensure immediate protection for the Coptic community, especially during the upcoming Christmas holiday,” Sarah Leah Whitson, Middle East and North Africa director at Human Rights Watch, said in a statement. “The victims deserve a credible, transparent investigation that brings the perpetrators to justice and is crucial for ending such attacks.”