An Islamist activist on Thursday hacked the Facebook page of feminist group Femen's Tunisian branch and posted religious messages after images of two members of the group posing topless were published on the Internet.
"Thanks to God we have hacked this immoral page and the best is yet to come," read one message signed by "Al-Angour".
"The page has been hacked and God willing, this debauchery will disappear from Tunisia," read another.
The hacker also posted videos showing Koranic verses and images of the Islamic profession of faith in Arabic.
The site itself had not published photos of the young Tunisian women, who nevertheless posted topless pictures of themselves elsewhere, with "My body belongs to me" and "Fuck your morals" written in black across their breasts.
The Ukrainian group Femen, which has inspired woman to bare their breasts in Moscow, Paris and even St Peter's Square in the Vatican, has been making headlines since 2010 for its topless feminist, pro-democracy and anti-corruption protests.
Femen Tunisia has never organised topless protests, with possible jail terms for indecency, but for weeks there has been speculation in the local press about Ukrainian and French feminists staging such a demonstration in the Muslim country.
Tunisian women have since the 1950s enjoyed legally backed equality of the sexes in several domains, a unique right in the Arab world, but they are still discriminated against in areas, particularly in inheritance cases.
Feminist NGOs have often accused the Islamist party Ennahda, which came to power after the revolution that overthrew Zine El Abidine Ben Ali's regime in 2011, of seeking to roll back women's rights as part of its efforts to Islamise society. They say those rights must be enshrined in the new constitution.