Six months after Tunisia's uprising, religious tension is rising over the limits of freedom of expression, as Islamists challenge the dominance of liberals in what was once a citadel of Arab secularism.

Police later arrested 26 men, but Salafists -- a purist trend within political Islam advocating a return to the ways of early Muslims -- gathered outside the justice ministry two days later to demand their release, leading to scuffles with lawyers.

Security forces were heavily deployed in central Tunis to stop protests by Salafists after Friday prayers last week.

Secular media and intellectuals have reacted with alarm, warning that freedoms in Tunisia -- a bastion of secularism under 23 years of tough police rule by Zine al-Abidine Ben Ali -- are in danger of being lost if Islamists across the spectrum of Islamist politics are not stopped.

"This is a foretaste of what awaits us if firm measures are not taken against these sorcerers' apprentices, since nothing will stop them attacking hotels, nightclubs or ordinary people sitting in a restaurant," wrote Taieb Zahar in the French-language monthly Realites.

Abdelmajid Habibi, a leader in the Salafist Tahrir party which police accused of staging the cinema attack, said the arts community was trying to provoke Salafists but misjudging the mood among ordinary Tunisians who are more conservative than the father of the modern state, Habib Bourguiba, imagined.

"The country doesn't need to show a film like this or with this name, especially with the situation Tunisia is going through now. This is a deliberate attempt to provoke people," he said, pointing to the film's Arabic title 'La Allah, La Sayyid' (No God, No Master) which he said hints there is no god.

Yes, the Tunisian people do not live the Islamic way, but they are not secular. Society isn't those who appear on television (talkshows). They have no popularity, they are a minority among Tunisians," Habibi said.

Fani's documentary, which calls for protecting secularism in post-Ben Ali Tunisia, was "like a declaration of war, and people wanted to say that they were against it," Habibi added.

An avowed atheist, Fani is a lightning rod for Islamists who has campaigned for removing an article in Tunisia's constitution naming Islam is the religion of state. She says it precludes the rights of Jews, Christians, atheists and others.

"There is a battle now to make people understand better that if we are to safeguard the liberty gained in ousting the dictator, we must protect all liberties," she said, speaking from France.

"What is clear is that there are many who want to live religion as they want. In Tunisia today I do not have the right to say that I do not believe in God."

By Andrew Hammond

Reuters