VATICAN CITY (AP) - Pope Francis is presiding over a Good Friday service in St. Peter's Basilica ahead of the re-enactment of Christ's crucifixion at Rome's Colosseum.

Security has been tightened around Rome for this year's Holy Week commemorations, which have coincided with a spate of arrests of suspected Islamic extremists.

Francis lay prostrate in front of the altar at the start of the chant-filled evening service. Later Friday, Francis travels to the Colosseum to preside over the Way of the Cross procession, the meditations of which were composed this year by Catholic students.

The solemn commemorations coincide with a new communications controversy in the Vatican over the pope's reported assertion that Hell doesn't exist. The Vatican hasn't denied the comments in the La Repubblica newspaper, saying only that the journalist reconstructed a conversation.

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