Tunisia said it was banning all demonstrations on Friday after receiving a tip-off about preparations for violence over cartoons of the Prophet Mohammed published by a French satirical weekly.
"The interior ministry, using its powers under the state of emergency and in order to maintain public order, announces that it is outlawing any form of demonstration anywhere in Tunisian territory on Friday," a ministry statement said on Thursday.
"The ministry notes that it has received information suggesting the protests would be exploited for the purpose of committing acts of violence and causing unrest."
Calls for Friday protests were circulating on social networks following the publication by French weekly Charlie Hebdo on Wednesday of cartoons featuring obscene images of the founder of Islam.
The interior ministry called on "all Tunisians and civil society to demonstrate understanding" and "urge (people) not to follow the call" to protest.
The ministry of religion also urged Tunisians to avoid falling into the trap of "deliberate provocation" that it said were what the controversial cartoons of the Prophet amounted to.
"They are a deliberate provocation designed to offend the religious sensibilities of Muslims, with the aim of fomenting trouble in Arab Spring countries," it said in a statement.
The French embassy has announced it will close on Friday, after it said all French schools in Tunisia would remain shut from Wednesday until Monday morning, as a precautionary measure.
Tunisia's ruling Islamist party responded to the printing of the cartoons by saying Muslims had "the right to protest" against them, as long as they do so peacefully.
"Ennahda backs the right of Muslims to protest and calls on the use of peaceful and civilised means," said Ennahda, which heads Tunisia's governing coalition, while also branding the cartoons "a new attack against the Prophet."
But the ministry of religion, which is headed by an Ennahda member and former imam, also warned of a "handful" of extremists seeking to incite "chaos and sedition" in Tunisia, condemning for the first time the country's Salafist movement.
"Among those who have imposed their control on certain mosques, a handful make radical speeches, inciting hatred and chaos, advocating violence and callling for civil disobediance."
"Their speeches are against the law, and against Islam, and proceed from ignorance and fanaticism," it added.
Publication of the cartoons comes against a background of violent protests across the Muslim world, which first erupted early last week over an anti-Islam film made in California and posted on the Internet.
Four people were killed and dozens wounded last Friday during a demonstration by hardline Salafists outside the US embassy in Tunis, with protesters hurling petrol bombs and storming the mission, while police fired live rounds and tear gas.
The security forces have been sharply criticised for their handling of last week's deadly unrest, which saw police overwhelmed by protesters for long periods, despite ample warning and attempts to boost security around the US mission.
Interior Minister Ali Larayedh has recognised that the security forces "stumbled," but insisted they had averted a "catastrophe" and has rejected numerous calls for his resignation over the issue.
In recent weeks, Tunisia has seen a spate of disturbances by Islamist hardliners of the Salafist movement that have escalated in the face of the US-produced movie "Innocence of Muslims."
Tunisia's Islamist-led government is regularly accused by the opposition and NGOs of not doing enough to rein in the extremists.