PARIS — France’s minister for women’s rights came under fire on Thursday for saying Muslim women who wear veils were like black slaves in favor of slavery.

An online petition with more than 18,000 signatures accused her of racism.

“Of course there are women who choose (to wear the veil). There were African negroes, American negroes who were for slavery. I believe that these women, a lot of them, are militants for political Islam, and I confront them as militants, … for the project for society that they represent,” the minister, Laurence Rossignol, said in an interview on BFM TV on Wednesday.

She was later reported to have apologized for the use of the word negro, but stood by her comparison of veil wearing to slavery.

“I strongly denounce these suggestions which stigmatize Muslim women,” Abdallah Zekri, president of the National Observatory on Islamophobia.

Rossignol is a strong proponent of a French political tradition that seeks to keep religion separate from political and educational life.

The approach has created tensions in France about the wearing of religious symbols in schools and other public places. France has a Catholic heritage and is also home to the biggest Muslim and Jewish populations in Europe.