Thieves broke into a small church in the mountains, east of Rome over the weekend and stole a reliquary with the blood of late Pope John Paul II.

Some of John Paul's blood was saved after an assassination attempt that nearly killed him in St. Peter's Square on May 13, 1981.

Franca Corrieri, custodian of the reliquary, said she had discovered a broken window early on Sunday morning and called the police.

She said when they entered the small stone church they found the gold reliquary and a crucifix missing.

Corrieri said the incident felt more like a 'kidnapping'' than a theft as she could not say if the intention of the thieves may have been to seek a ransom for the blood.

She said apart from the reliquary and a crucifix, nothing else was stolen from the isolated church, even though the thieves would probably have had time to take other objects during the night-time theft.

Reuters reports that John Paul, who died in 2005, loved the mountains in the Abruzzo region east of Rome and sometimes slip away from the Vatican secretly to hike or ski there and pray in the church.

It said that the Polish-born John Paul, who reigned for 27 years, was due to be made a saint of the Roman Catholic Church in May, meaning the relic would become more noteworthy and valuable.

In 2011, John Paul's former private secretary, Cardinal Stanislaw Dziwisz, gave the local Abruzzo community some of the late pontiff's blood as a token of the love he had felt for the mountainous area.

It was put in a gold and glass circular case and kept in a niche of the small mountain church of San Pietro della Ienca, near the city of L'Aquila.