Far-right youths clashed with left-wing activists who had gathered outside Notre-Dame Cathedral in Paris on Sunday to protest against Pope Benedict's opposition to condoms, a police source said.
About 30 ecologists and Communists threw condoms on the ground outside the cathedral, where worshippers were leaving Sunday mass.
One person was injured and three were arrested after clashes between the protesters and about 20 youths who the police source said were associated with the far-right and who were carrying placards saying "Leave my Pope alone".
Benedict said in Africa on Tuesday that the use of condoms was complicating the fight against AIDS, reaffirming the Roman Catholic Church's opposition to condoms.
The comments were criticised by French politicians from all parties.
Two surveys at the weekend showed the German-born pontiff's popularity in France has fallen sharply.
