Surrounded by armed soldiers and bloodstained walls, hundreds of mourners attended a memorial service Monday for the victims of a deadly Christmas Day blast at a Catholic church in Nigeria.

The priest of St. Theresa's, Father Isaac Achi, told the crowd that Sunday's attack made him cry for the first time in his life.

The St. Theresa's blast near Abuja killed 35 people. It was one of four coordinated explosions in Nigeria Sunday that killed at least 39 people. Two other churches were also attacked in the cities of Jos and Gadaka, and a car bomb blew up near secret police headquarters in Yobe.

Pope Benedict denounced the bombings as “absurd.” He appealed to pilgrims in the Vatican's St. Peter's Square to pray for the victims.

The radical Muslim sect Boko Haram has claimed responsibility for the attacks. It is the second consecutive Christmas that the group targeted churches.

Boko Haram, whose name means “Western education in sinful” in the Hausa language, wants to establish a strict Islamic state in Nigeria. It does not recognize the government or the country's constitution.

The country of 150 million is about evenly divided between Muslims, who mostly live in the north, and Christians who dominate in the south.

Hundreds of others have died this year in bombings and shootings blamed on Boko Haram.

( # # # aptn video/sound of pope/st. peter's square

reuters video/sound nigeria ))