Tunisia on Thursaday banned protests planned by hardline Islamists demanding a more religious state following the worst unrest since the 2011 uprising that gave birth to the Arab Spring.
The north African country has been rocked by three days of violence that left one dead and dozens wounded after ultra-conservative Salafists took issue with works at an art exhibition they deemed offensive to Islam.
Several wings of the Salafi movement, which advocates practising Islam as it was by the Prophet 14 centuries ago, had called for mass protests following Friday prayers but the interior ministry said no rally had been authorised.
"No march has been authorised by the ministry of the interior," spokesman Khaled Tarrouche told AFP, adding that "the law will be applied against all acts of violence... Some calls for violence are circulating on Facebook."
Whether the Salafists, who have been flexing their muscles since an uprising toppled longtime president Zine el Abidine Ben Ali in January 2011, call off their protests remains to be seen and police were already out in force Thursday.
In a video posted on the Internet earlier this week, a Salafist leader, Abou Ayoub, urged Tunisians to "rise up on Friday after the prayer, in response to those who mock Islam."
The Ansar al Charia movement headded by former jihadist Abou Iyadh also called for nationwide protests.
The art exhibition in a Tunis suburb featured a painting of naked woman with bearded men standing behind her and a work spelling the world "Allah" with a file of ants.
The works were condemned by some as blasphemous and were destroyed Sunday night in an act blamed on Salafists.
The incident sparked clashes across the north African country between Monday and Wednesday that saw police stations and political party offices torched.
One person was killed and more than 100 injured, including 65 policemen.
Authorities arrested more than 160 people and slapped a curfew on several regions, including the greater Tunis area, which was shortened on Wednesday by two hours to apply from 10 pm to 4 am.
As artists protested that freedom of expression was being undermined, the government condemned the attack against the exhibition but with Salafists threatening mass action, the gallery was closed nonetheless.
The moderate Islamist party Ennahda (Renaissance), which dominates the government and the national assembly, called Wednesday for "a peaceful march to defend the revolution and sacred values".
Tarrouche said that the ban also applied to this planned march.
After three days of violence, a joint statement by the leaders of Tunisia's government, constituent assembly and presidency condemned "extremist groups who threaten freedoms," in a thinly veiled reference to the Salafists.
The government is led by Ennahda while the presidency and post of parliament speaker are held by the two parties that came closest to it in October's first post-revolution polls.
The ruling trio also pointed a finger at former members of the ousted Ben Ali regime, who have been accused of instrumentalising Salafist groups to stoke tensions between Islamists and secularists and destabilise the country.
The joint statement cited "the ghosts of the fallen regime trying to sabotage the transition process" at a time when Tunisia is fashioning post-revolution institutions and drafting a new constitution.
"The situation is very unclear. I took a close look at the protests that took place in Carthage on Monday, there were as many fake Salafists as there were real ones," Alaya Allani, an expert on regional Islamist groups, told AFP.
He said the Salafists themselves were divided in two main camps, with one wing seeking to emulate its Egyptian colleagues and join the political fray and the other recruiting thugs to sew chaos.