Pope Francis has conveyed his closeness to the victims of a deadly bombing at a Mass in southern Philippines on Sunday that claimed at least four lives and injured dozens others.

“I wish to assure my prayer for the victims of the attack…,” the pope sad following his weekly recitation of the Angelus prayer on Sunday.

“I am close to the families and the people of Mindanao, who have already suffered so much,” he said.

The attack was carried out in the Marawi State University gymnasium, where the Mass was being celebrated for the first Sunday of Advent.

In the Catholic Church, Advent is the four-week liturgical season that precedes Christmas.

In a separate message to Bishop Edwin de la Peña of the Prelature of Marawi, the pope said he was “deeply saddened” by the “injuries and loss of lives caused by the bombing”.

The pontiff, who visited the Philippines in 2015, also appealed to “Christ the prince of peace (to) grant to all the strength to turn from violence and overcome every evil with good.”

Marawi was besieged by the Islamic State-influenced Maute group in 2017, which left the city in rubble.

The country’s Catholic bishops have immediately condemned the violence and demanded justice for the victims.

“Such violence should not only be denounced; it should also be renounced as a way of seeking redress by every peace-loving Filipino,” said Bishop Pablo Virgilio David, president of the bishops’ conference.

“…We reaffirm our relenting commitment to peace and our repudiation of violence,” he added.

Cardinal Orlando Quevedo, the archbishop emeritus of Cotabato and a prominent Mindanao peace advocate, described the attack as “a crime that literally cries out to heaven.”

“The massacre is the most terrible and most damnable terroristic crime against innocent worshippers on a Christian holy day,” said Quevedo.

The cardinal, who is also a member of the Council of Leaders of the Bangsamoro Autonomous Region in Muslim Mindanao (BARMM), also joined in appealing to authorities “to ferret out the perpetrators of this heinous crime and bring to justice”.

“For the victims and for their grieving families, my deep personal condolences and prayers. Let peace begin in our hearts,” he said.