Nine members of the radical feminist group Femen have been acquitted over a topless protest in Paris's Notre Dame cathedral in response to the news that Pope Benedict XVI was to quit as head of the Catholic Church.

The activists stripped to their knickers and bared their breasts, stunning bystanders at the holy site. They displayed messages scrawled in pen on to their body such as "pope no more" "saved by the bell" and "bye bye Benedict". Some of the Femen members were punched in the face by angry Catholics before being escorted out of the church by security stuff.

They were accused of degrading a place of worship after bashing with a hammer an enormous bell on display in the 12th century church to celebrate the outgoing Pontiff.

The Paris court's decision to clear the charges was enthusiastically greeted by Femen. The protest was staged during a period of violent rallies against a law that legalised same-sex marriage in France.

After the Femen demonstration, a 78-year-old rightwing author shot himself through the mouth in front of Notre Dame ceremonial table after posting on his blog a damning critique of the same-sex marriage bill, and called for "spectacular and symbolic actions [to] awaken consciences".

Dominique Venner's suicide was described as "political" by far-right French politician Marine Le Pen, a vocal critic of the same-sex marriage bill pushed by President Francois Hollande.

A lone Femen activist reacted to Venner's death staging a fake suicide in front of the same ceremonial table. With the words "May fascists rest in hell" emblazoned across her naked chest, the woman pointed a fake gun into her mouth next to the altar.