Thousands of Tunisian Islamists and secularists staged parallel protests outside the interim parliament on Saturday in a dispute over how big a role Islam should play in society after the country's "Arab Spring" revolution.
Tensions have been running high between the two camps since the revolt in January scrapped a ban on Islamists and paved the way for a moderate Islamist party to come to power at the head of a coalition government.
The latest round of protests was sparked when a group of hardline Islamists occupied a university campus near the capital to demand segregation of sexes in class and the right for women students to wear a full-face veil.
About 3,000 Islamists gathered outside the constitutional assembly in the Bardo district of the Tunis on Saturday, separated by a police cordon from a counter-protest by about 1,000 secularists.
The Islamists say the secularist elite which has run the country since independence from France is still restricting their freedom to express their faith. Their rivals say the Islamists are trying to impose an Islamic state in what has been one of the Arab world's most liberal countries.
The Islamist protesters at the rally carried placards saying: "We support the legitimacy of the majority!," "Islamic Tunisia is not secular!," and "No to secularist extremism."
An Islamist protester, Nourdine Machfer, said the Tunisian people had expressed their will when they handed victory to the moderate Islamist Ennahda party in an election in October.
"It's bizarre. Today in Tunisia we are living in a dictatorship of the minority," Machfer told Reuters. "They should respect the will of the people, who have made their views known.
Ennahda issued a statement saying that it did not support the Islamist protest outside parliament.
However, secularist opponents said they believed Ennahda's true agenda was to create an Islamic state by stealth.
"The Islamists ... want to use the constitution to take power, and stage a coup d'etat against democracy," said one of the secularist protesters, Raja Dali.
"They want to give all the power to the prime minister," she said, referring to senior Ennahda official Hamadi Jbeli who is his party's nominee to lead the coalition government.
Tunisia's struggle to reconcile the rival camps is being watched closely in Egypt, where an Islamist-affiliated party performed strongly in the first phase of a parliamentary election.
Tunisia became the birth-place of the Arab Spring when a vegetable seller, Mohamed Bouazizi, set fire to himself in protest at government repression. His suicide prompted a wave of unrest which forced president Zine al-Abidine Ben Ali to step down.
Tunisia's revolution inspired revolutions which ousted entrenched rulers in Libya and Egypt, as well as upheavals in Syria and Yemen.
Saturday's protest was the first time that both Islamists and secularists had staged simultaneous protest. Shouts and jeers were exchanged between the two groups but there were no clashes.
Ennahda is in an awkward position because it wants to be seen to be defending the rights of Muslims to express their faith but at the same time it is wary of alarming secularists and Western governments by appearing too close to Islamist hardliners.
The latest flare-up of tension is complicating efforts by Ennahda and its two secularist coalition partners to agree on the make-up of a coalition government.
It is also distracting the country's new rulers from addressing the high unemployment and low incomes that are the main preoccupation for ordinary Tunisians.
One young man on Saturday stood between the rival crowds with tape over his mouth, a loaf of bread in his hand, and a placard which read: "I am with neither of you.. I am in favor of jobs and dignity."