Mourners filled an Egyptian church on Monday for the funeral of 24 victims who lost their lives in a bomb attack at Cairo's Coptic cathedral.

The spiritual leader of Egypt's Orthodox Christians, Pope Tawadros II, called for unity during Monday's service, saying the bombing was an attack "against the nation."

"We know that whoever has done this does not belong to Egypt, its history or its civilization," he said in a wavering voice.

The wooden coffins were transported to a nearby memorial cenotaph for a state funeral attended by Egyptian President Abdel-Fattah el-Sissi.

Hundreds of people gathered outside of the church, some of whom were angry with security forces who they say did not do enough to prevent the bomb attack.

Sunday's bombing took place during a mass service in the women's section of St. Mark's Cathedral. The blast shattered windows, scattered pews and covered the walls in ball-bearing-sized shrapnel.

The health ministry revised the death toll to 24 on Monday. At least 45 people were wounded, and 21 were still hospitalized, the ministry said. Most of the victims of the blast were women.

It was among the deadliest attacks to ever target Egypt's Coptic minority which makes up around 10 percent of the country's population.

Suicide bomb attack

The cathedral attack was caused by a suicide bomber, Sissi said later at the state funeral. Security officials previously said they believed the bomb contained 12 kilograms (26 pounds) of TNT.

He identified the attacker as 22-year-old Shafiq Mahmoud Mohamed Mostafa. Egyptian authorities had already arrested three men and one woman in connection with the attack, Sissi added. Police were still searching for two suspects, but no further information was released.

Addressing Pope Tawadros II, Sissi said: "We would not have been able to come to you today, your holiness, before getting some information." He also called for tighter laws to help prevent future attacks.

There was no immediate claim of responsibility.

Coptic Christians have been previously targeted by their Muslim neighbors. The last major attack on a church in Egypt took place in 2011 as worshippers left a New Year's service in Alexandria. At least 21 people were killed and no one was punished.

rs/jm (AP, AFP, dpa, Reuters)