Topless FEMEN protestors wearing nuns habits stormed French protests against gay marriage this weekend.
More than 100,000 people organised by Catholic groups joined the marches against government plans to legalise same-sex marriage in the new year.
The groups are opposed to President Francois Hollande's draft law, which also proposes to allow gay adoptions.
Topless FEMEN members clashed with same-sex marriage protesters
Members of the Ukrainian group FEMEN crashed the protests, chanting "In gay we trust" and sprayed white powder from bottles.
Scuffles broke out, resulting in some of the women being hit and knocked to the ground, The Washington Post reported.
The FEMEN website claims: "Religious nationalists violently attacked FEMEN sextremists during the protest 'In gay we trust'. The aggression of Catholics has been stopped by police and members of the LGBT community."
Up to 100,000 people across France took part in the protests against same sex marriage
It adds: "Breaking into the crowd dressed as nuns, activists will copiously irrigate the integrist demonstrators with Jesus' semen eroded from balloons."
On its Facebook page FEMEN claims two of its activists suffered a broken tooth and a bloody nose in the skirmishes.
The same post states: "FEMEN promises not to forget this incident and to take revenge on the organisers in the best Christian tradition: An eye for an eye, a tooth for a tooth."
The protesters carried posters reading: "One father + one mother for all children", and chanted: "Shame on the president, who'll protect the infants?"
Some of the protesters were thrown to the ground in the clashes
Polls show around 60 per cent support for the gay marriage, but not for gay adoptions. Same sex marriage was one of Hollande's campaign promises and his government plans to legalise it by mid-2013.
A Parisian couple marching on Sunday with two of their four children, told Reuters they knew the law would eventually pass, "But we wanted to show our disapproval."
FEMEN protested in support of Russian punk band Pussy Riot, holding aloft signs saying 'f**k Putin' and 'Free Pussy Riot'.
FEMEN were founded in 2008 and their unique form of protest has since spread. The group held demonstrations in London protesting the Olympics' "support" for radical Islamist regimes.