SOUTH END -- “The power of children’s prayer is incredible,” said Father Edward Riley, recently appointed pastor of St. Joseph Parish in Holbrook, at Boston’s second annual Children’s Eucharistic Holy Hour on Oct. 5. Father Riley is also spiritual director for the World Apostolate of Fatima in Boston, which sponsored the event.

Similar holy hours are held internationally through the World Apostolate of Fatima, a public association of the faithful. These holy hours began five years ago.

This year at the Cathedral of the Holy Cross, the holy hour gathered 350 children from Catholic schools in the Archdiocese of Boston to pray the rosary, adore Jesus in the Eucharist and commemorate the 90th anniversary of the Fatima apparitions. The students were encouraged to heed the message of Our Lady of Fatima and pray the rosary daily for peace, families and the whole world.

Three of the students dressed as the shepherd children -- Lucia, Jacinta and Francisco -- that Mary appeared to in Portugal in 1917. They knelt before a statue of the Blessed Mother for the first part of the service.

During the service, Father Riley asked the children to pray that Blesseds Jacinta and Francisco are canonized and become a model for boys and girls always. Lucia, the oldest of the three children, is still living.

Bishop John A. Dooher, who presided at the service, encouraged the children to also look to Mary as a model. Mary was a young girl when the angel Gabriel told her she would be the mother of Jesus, he said.

“Mary said ‘yes’ to the will of God even though she didn’t understand everything that ‘yes’ would mean. She trusted that God would be with her,” the bishop continued.

Mary always wants what God wants, and she asked the children at Fatima to pray for the people of the world to turn to Jesus and listen to his message, he said.

Bishop Dooher also emphasized the universality of the Catholic Church and the children’s holy hour.

“We’re invited this day with the whole world in honoring Mary and recognizing Jesus in the Blessed Sacrament,” he said, adding that the prayer of the rosary is unceasing because somewhere in the world there are Catholics praying the rosary at all times.

Father Riley encouraged the children to sacrifice for Jesus when someone hurts their feelings, when they stub their toes or when they are asked to do something they really do not want to do.

Together the children prayed the World Mission Rosary with the luminous mysteries.

Jaymie Stuart Wolfe, who directed the music ministry for the holy hour, explained to the children, “We do so as a way of asking God to fill families of the whole world with the light of his love and truth.”

During the rosary, there was a Gospel reading from Mark where Jesus tells the disciples to bring the little children to him. Then, prayer petitions from each school along with candles and red and white roses were brought forward by students and left at the foot of the altar. The hour concluded with Benediction and song.

“Holy God we praise thy name. Lord of all we bow before thee,” the children sang. “Infinite thy vast domain, everlasting is thy reign.”

The children from St. John School in the North End stayed after the conclusion of the service to walk through the cathedral.

Michael Salvati, a fifth grader, said of the cathedral, “It’s very big.”

He and many of his fellow classmates had never visited Holy Cross Cathedral.

“It’s good for kids to come here and pray for a holy hour,” he said.

Shona Ortiz, a third grader, said the cathedral was “pretty.” She added that she thought it was “fun” to pray the rosary but that she had not known that at every moment Catholics all over the world are praying the rosary.

“I’m surprised that it’s happening all the time,” she said.

Fourth grader Ivana Bonetti said her favorite part was when the statue of the Madonna was carried in.

“I like her a lot,” she said.

About the event as a whole, she said, “It made me know about stories I hadn’t heard, and I learned new songs.”

Father Riley said that the annual event communicates to the children the importance of growing in relationship with Jesus Christ.

“It brings children together before Jesus in the Blessed Sacrament,” he said. “They recognize how many other children believe in the Catholic faith.”