French far-right activist Dominique Venner shot himself at Notre Dame cathedral in Paris on Tuesday, three days after President Francois Hollande signed a gay marriage bill into law.

Venner, 78, shot himself in the mouth and collapsed on to the cathedral's altar, creating a panic among tourist and forcing the evacuation of one of Paris' most iconic buildings.

Police said that he carried a letter, the contents of which have not been released, but made no declaration before taking his own life, Reuters reported.

However, Venner appeared to be taking his own words to heart. He had written in a blog post that preventing passage of the marriage bill would require “spectacular and symbolic actions to wake up the sleep walkers.”

“We are entering a time when words must be authenticated by acts,” he wrote.

The law, which also legalizes adoption for gay couples, is expected to take effect later this month.

(Related: France's first gay wedding set for May 29.)