By Philip Pullella
VATICAN CITY (Reuters) - Pope Francis presided at a Good Friday service where he heard the Vatican's official preacher accuse the international community of indifference to the persecution of Christians, a day after Islamist militants attacked a university in Kenya, killing at least 147 people.
Father Raniero Cantalamessa, whose title is "preacher of pontifical household," referred to the attack, in which the Al Shabaab militants initially killed indiscriminately but later freed some Muslims and targeted Christian students during a siege that lasted about 15 hours.
The long "Passion of the Lord" service, during which the pope prostrated in prayer on the marble floor of St. Peter's Basilica on the day Christians commemorate Jesus' crucifixion, is one of the few times he listens while someone else preaches.
Cantalamessa weaved his sermon around the plight of Christians today.
"Christians are of course not the only victims of homicidal violence in the world, but we cannot ignore that in many countries they are the most frequently targeted victims," he said.
Cantalamessa denounced "the disturbing indifference of world institutions and public opinion in the face of all this killing of Christians ...".
Besides the Kenya killings, he mentioned the beheading of 22 Egyptian Coptic Christians last February by Islamic State militants in Libya.
Later on Friday, the second of four days of papal activities culminating on Easter Sunday, Francis was due to lead a candlelight "Way of the Cross" procession around the ruins of Rome's Colosseum.
On Saturday night, the leader of the world's 1.2 billion Roman Catholic celebrates an Easter Eve service in St. Peter's Basilica and on Sunday he delivers his twice yearly "Urbi et Orbi" (to the city and the world) blessing and message.
The pope earlier on Friday condemned the Kenyan university attack as "senseless brutality".
Francis has expressed alarm over the plight of Christians targeted for their faith and has said the international community would be justified in using military force as a last resort to stop "unjust aggression" by Islamic State.
(Reporting By Philip Pullella; Editing by Larry King)