France plans to close its embassies, consulates, cultural centers and schools in 20 countries Friday as a precautionary measure after a French satirical magazine published cartoons featuring the Prophet Muhammad.

The country's foreign minister says security is being increased at French diplomatic posts as government and religious leaders call for restraint.

The weekly magazine Charlie Hebdo featured several images of the prophet in its Wednesday issue, including several of him naked. Its offices in Paris were fire-bombed last year after it published a mocking caricature of Muhammad.

Also Wednesday, French Prime Minister Jean-Marc Ayrault said that a request by organizers to hold a protest in Paris Saturday against an anti-Islam film produced in the United States will be refused.

Meanwhile, U.S. Secretary of State Hillary Clinton says the United States is taking aggressive measures to protect its diplomats as protests against the film continue.

Demonstrations prompted the American consulate in the Indonesian city of Medan to temporarily close on Wednesday, following a similar move by the U.S. Embassy in Bangkok, Thailand a day earlier. Protests also took place Wednesday in the Pakistani capital, Islamabad and in the eastern Afghan city of Jalalabad.

Clinton said Tuesday that officials are reviewing security at every post and adjusting as necessary.

She also says the Libyan government is helping American investigators probe last week's attack on the U.S. consulate in Benghazi that killed the U.S. ambassador and three other diplomats.

Fury about the low-budget film that insults the Prophet Muhammad sparked protests, some of them violent, including at the U.S. Embassy in Tunisia.

Tunisian Foreign Minister Rafik Abdessalem has condemned the attack, saying political violence is not acceptable and that such an incident will never happen again. He promised to pursue those responsible for the violence.