Tunisia banned all demonstrations on Friday and Western missions across the Arab world went on high alert amid fears of new violence over a US-made film mocking Islam and cartoons of the Prophet Mohammed in a French magazine.
France closed its missions, schools and cultural centres in 20 countries for the day. Those in Tunisia were ordered shut from Wednesday, those in Egypt from Thursday.
Islamist groups were organising planned rallies in several countries but security forces were on alert across the region for spontaneous demontrations after the main weekly Muslim prayers at noon -- a traditional focal point for protest.
In Libya's second city Benghazi -- where US Ambassador Chris Stevens and three other Americans were murdered last week in what Washington now says was a terrorist attack -- an Islamist militia called for demonstrations against France and the United States.
The planned protest has the potential for violence as militia opponents planned a "Save Benghazi" rally to demand that central government tame the armed groups that have retained huge power since the Western-backed uprising that overthrew dictator Moamer Kadhafi last year.
Demonstrations were also planned among both Sunni and Shiite Muslims in Lebanon, and among Palestinians in the occupied West Bank.
The Tunisian interior ministry said it was invoking emergency law powers to impose the nationwide demonstration ban following tip-offs of preparations for violence by hardliners.
"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," it 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.
In an exclusive AFP interview, the veteran leader of the moderate Islamist Ennahda party that leads the coalition government said the authorities had learnt the lesson of deadly distrubances outside the US embassy on September 14 and said he expected no repetition of such violencea.
"Each time that parties or groups overstep our freedoms in a flagrant manner, we have to be tough, clamp down and insist on public order," Rached Ghannouchi told AFP.
"These people pose a threat not only to Ennahda but to the country's freedoms and security.
"The police have learnt the lesson and I don't think there's going to be any repetition (this Friday)," he said.
Four people were killed and dozens wounded when last week's demonstration outside the US embassy and adjacent American School turned violent.
It took the security forces, who fired live rounds and tear gas in response, nearly three hours to bring the violence under control.
In Tehran on Friday, Iranian President Mahmoud Ahmadinejad said he did not believe for one moment the repeated insistence of US officials that the administration had nothing to do with the low-budget movie "Innocence of Muslim' produced by an extremist Christian group.
He said US government claims it could do nothing to censor the film were a "deception" exploiting the pretext of freedom of expression.
He called the film an Israeli-hatched plot "to divide (Muslims) and spark sectarian conflict."