A small explosive device went off outside a French church in central Rome, causing only material damage in an incident one official at France's embassy to the Vatican said could be linked to President Francois Hollande's visit Friday.
"A handmade bomb went off at 2:30 am (0130 GMT), damaging three parked cars and the windows of a nearby building," a police spokesman told AFP.
"There has been no claim of responsibility," he said.
The blast happened in Vicolo della Campana and an official at the secretariat of France's embassy to the Holy See said the small street only had the church of Saint-Yves des Breton and a restaurant on it.
"One of the theories is that this act was linked to the visit by the president," the official said.
A spokesman for the French embassy in Rome told The Local they were waiting for more information from the police and would not speculate over whether the planting of the device was linked to Hollande's visit.
Police are investigating on the site of the blast.
Pope Francis received Hollande later on Friday morning for the first meeting between the two, amid deep divisions in France over hot-button issues including abortion and gay marriage.
Hollande may have braced himself for a rough ride with Pope Francis. After legalising gay marriage, softening laws on abortion, vowing to explore a change to euthanasia and allegedly being caught having a fling, Hollande may have some explaining to do.
Abortion and euthanasia will be among hot button issues on the table Friday when Pope Francis meets embattled French President Francois Hollande, under pressure after revelations of an affair but hoping to woo back Catholic voters.
Francis has largely avoided public diatribes on Church doctrine but Vatican watchers say he is likely to press the Socialist leader on issues including changes to abortion legislation and a drive to legalise euthanasia.
"They will certainly not play hide-and-seek. There will be no holds barred," a high-ranking prelate told AFP on condition of anonymity.
The 59-year-old Hollande is plagued by low popularity and hopes to reconcile with a Catholic electorate largely hostile to his liberal policies.
He sees the visit as a chance to send "a strong message of dialogue and attention to the Catholics," an advisor said at a briefing ahead of the trip.
But French priest and blogger Stephane Lemessin does not believe French Catholics will be won over by Hollande's visit to the Pope.
"Catholics in France will not be influence. For them they remember gay marriage. Hollande probably hopes he can win some support, that's why all politicians visit the pope," Lemessin told The Local.
"I think their talks will mostly be about international issues like poverty and Syria rather than French issues," he said.
Lemessin also said Hollande's recent scandal around his personal life will not affect the trip.
"He is not the first French president who had issues their personal life, to visit the Pope. Sarkozy went to the Vatican after getting a divorce. These stories will not interest the Pope. He is very discreet," Lemessin said.
He may also be hoping some of the pontiff's popularity rubs off on him.
His quest will be made no easier by lawmakers' decision this week to greenlight a change in the country's abortion laws, effectively making it easier for a woman to terminate a pregnancy.