Police in Tunis used tear gas on Sunday to try to disperse hundreds of Islamists who were attacking them with stones, knives and batons, the biggest clashes over religion in the Tunisian capital for several years.

Tension is mounting before an election later this month, the first since a revolution toppled Tunisia's autocratic leader, that will pit Islamists free to express their beliefs for the first time against secularists who say their liberal values are under threat.

The Islamists were protesting against a ban on women who wear the niqab, or full-face veil, enrolling in university, and the decision by a Tunisian television station to broadcast animated film “Persepolis” which they said denigrated Islam.

Several hundred protesters gathered outside the main university campus in Tunis, and from there went to the working-class neighborhood of Jebel El-Ahmar, north of the city center, where the clashes with police broke out.