Following the unrest in the Muslim world over an obscure American film that ridicules the prophet Mohammed, security officials in Jerusalem will be on high alert on Friday.

Thousands of police are to be deployed from the early hours on Friday morning in sensitive locations around the city. Police and border police forces will be stationed near the Temple Mount, in an effort to maintain order as Muslims gather there for Friday prayers. Officers will also be in alleyways of the Old City, other Arab neighborhoods of Jerusalem and in areas in which Arab and Jewish neighborhoods meet.

Police have vowed to quash any attempt to disturb the peace. The caution comes against the backdrop of violence in the Arab world, including in Egypt, Yemen and Libya, where U.S. Ambassador J. Christopher Stevens and three other Americans were killed on Tuesday. The violence may have been sparked by an anti-Muslim film, "Innocence of Muslims."

The U.S. consulate general in Jerusalem issued an advisory that the Old City would be off limits to U.S. government personnel today due to the possibility of demonstrations against the film, and advised other Americans to "defer non-essential travel to the Old City" and to be generally careful.

Initial news reports said the film was produced by a man who identified himself as Sam Bacile, an Israeli Jew living in the United States. But those reports were later discredited. It now seems Bacile is actually an American Coptic Christian named Nakoula Basseley Nakoula.

On Thursday, deputy Foreign Ministry spokesman Paul Hirschson slammed the initial reports that a Jew was involved. "This film has nothing to do with Israel. The people who produced it, who, it is now apparent, do not include Israelis or Jews, have nothing to do with us," Hirschson told the German news agency DPA.

"The content of the film is beneath contempt, it is a vile film," he said, adding that Israel did not know anything about the alleged director of the film. "We have no knowledge that this supposed person is Israeli," he said.

In the U.S., the American Jewish Committee and the Anti-Defamation League also expressed concern over the media's coverage of the story.

The website theatlantic.com quoted a Christian activist, Steve Klein, who supposedly worked as a consultant on the film, as saying that Bacile was not Israeli or Jewish and that his name was a pseudonym.

Demonstrations were held in Gaza City and in Tel Aviv yesterday to protest the film. Witnesses in Gaza City said several dozen protesters burned American and Israeli flags and chanted, "Death to America! Death to Israel!" They also burned black-and-white pictures of the film's presumed producer.

Some men waved black flags of the Popular Resistance Committees, a radical armed faction.

The protests took place near the headquarters of UN agencies such as UNRWA, which assists Palestinian refugees, and the UN's Office for the Coordination of Humanitarian Affairs. International organizations shut their offices for 24 hours as a precautionary measure.

In Tel Aviv, several dozen members of the Islamic Movement's northern branch protested outside the American embassy. Protesters carried signs denouncing the film. Protesters claimed that the U.S. government sponsors "little people" who hurt Islam and Muslims.

The movement's southern branch was scheduled to hold a similar protest today in Rahat on Friday.