Tunisian President Moncef Marzouki on Wednesday said his country would support an Arab peacekeeping force in Syria, as nations struggle to find a solution to the conflict.

"A peacekeeping operation by Arab nations is something we could well imagine," Marzouki told Agence France Presse on the sidelines of a U.N. General Assembly.

Tunisian civil society groups expressed outrage on Wednesday after a young woman was accused of indecency by two policemen jailed for raping her, amid criticism of the Islamist-led government for rolling back women's rights.

The woman and her fiance were summoned by a magistrate on Wednesday to face the two policemen, both found guilty of rape and jailed, who accuse her of "indecency" and "assault," a group of Tunisian NGOs said in a statement.

The veteran leader of Tunisia's ruling Islamist party told Agence France Presse that the authorities would crack down on hardline Salafists after deadly violence around the U.S. embassy, saying they pose a threat to the country's freedoms and security.

"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," Ennahda chief Rached Ghannouchi told AFP in an interview.

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.

Oil-rich Saudi Arabia has distributed $3.7 billion in aid to countries touched by the Arab Spring, most of it to Egypt and Jordan, a report by the International Monetary Fund showed Wednesday.

Saudi Arabia, the Arab world's wealthiest country, has pledged nearly $17.9 billion in support for fellow Arabs since the pro-democracy revolt erupted in Tunisia in January 2010 and spread throughout the region, toppling and shaking authoritarian governments.

Around 100 U.S. citizens have been evacuated from Tunisia since an attack on the embassy in Tunis by angry Muslim protesters that left four people dead, several sources said on Monday.

"The American nationals were evacuated on Sunday," a diplomatic source told AFP, without saying how many had left the country.

The United States on Saturday ordered non-essential diplomatic staff and their relatives to leave Sudan and Tunisia following violent anti-American protests, and warned U.S. citizens against travel to those countries.

Tunisia's Interior Ministry threatened to punish all those involved in Friday's U.S. embassy attack that left four people dead and 49 injured after extremist protesters angry over the amateur film made in the United States stormed the installation.

Four people were killed and almost 50 injured in an attack on the U.S. embassy in the Tunisian capital on Friday by protesters angry over an anti-Islam film, the health ministry said.

"Three protesters were shot dead, the fourth was hit by a car and 49 people were injured, including nine seriously," a spokesman for the ministry told Agence France Presse on Saturday.

Tunisia said on Saturday that the "irresponsible actions" of demonstrators who attacked the U.S. embassy during a protest over an anti-Islam film would not affect its relations with Washington.

The Tunisian foreign ministry said it had "full confidence" that "these irresponsible actions... will not affect the friendly ties" between Tunis and Washington.

Three people were killed on Friday and another 28 wounded in clashes at the U.S. embassy in Tunis, which was stormed by an angry mob protesting a film mocking Islam, official media said, citing the health ministry.

Two of the injured were in a critical condition, the same source said, without giving any details about the victims.