Vandals and arsonists have targeted French churches in a wave of attacks that has lasted nearly two months.
More than 10 churches have been hit since the beginning of February, with some set on fire while others were severely desecrated or damaged.
St. Sulpice, the second-largest church in Paris, after Notre Dame Cathedral, had the large wooden door on its southern transept set ablaze March 17.
Investigators confirmed March 18 that the fire was started deliberately, according to the website of the Vienna-based Observatory on Intolerance and Discrimination Against Christians in Europe, an independent organization founded with the help of the Council of European Bishops' Conferences.
In early February, in the Church of Notre-Dame-des-Enfants in Nimes, near the Spanish border, intruders drew a cross on a wall with excrement then stuck consecrated hosts to it.
The tabernacle was broken and other consecrated hosts were destroyed, prompting Bishop Robert Wattebled of Nimes to issue a statement Feb. 8 to say that the desecration was so severe that the church building could not be used until penitential rites of purification had been carried out.
Carmelites, Cistercians and Poor Clares of the diocese offered fasting and prayer to atone for the desecration, and the rite of penance and purification occurred Feb. 13.
In a statement posted on the diocesan website to mark the occasion, Bishop Wattebled said purification was necessary because "the deepest meaning of the church ... has been for a moment abused, scorned and profaned," adding that the penitential rite did not absolve the perpetrators of their culpability.
Bishop Wattebled noted there had been a surge in attacks against Jewish sites throughout France. Likewise, the attacks on the churches have been carried out across the country.
The Church of St Nicholas in Houilles, in north-central France, was targeted by intruders who destroyed a statue of Mary and threw the altar cross to the floor, according to La Croix International, a Catholic daily.
Statues of saints were broken and an altar cloth set on fire in Saint-Alain Cathedral in Lavaur, in south-central France, while hosts were stolen from the Church of Notre-Dame in Dijon, in eastern France, and scattered on the ground.
Five of the attacks took place in just one week, leading French Prime Minister Edouard Philippe to denounce them on Twitter.
"In our secular republic we respect the places of worship," he tweeted. "Such acts shock me and must be unanimously condemned."
French media reported a 35-year-old man has confessed to police to carrying out the attack in Houilles, but the mystery surrounding the identities of other culprits has fueled speculation that the offenses might have been carried out by Islamic extremists, secularists or radical feminists.
In February, the French bishops expressed their solidarity with the country's Jews following the release of figures that showed a 74 percent increase in anti-Semitic attacks the previous year, with 541 crimes documented in 2018. Most attacks involved physical violence and abuse, the daubing of shops and desecration of monuments and cemeteries.