Iran's hard-line president on Saturday accused the United States and Europe of being "hostages of Zionism" and said they should pay a heavy price for the publication of caricatures of the Prophet Muhammad that have triggered worldwide protests.

Denmark — where the drawings were first published four months ago — warned Danes to leave Indonesia, saying they faced a "significant and imminent danger" from an extremist group and announced it had withdrawn embassy staff from Jakarta, Iran and Syria.

Yemen announced that three chief editors of privately owned Yemeni papers will stand trial for printing the Danish cartoons and their publishing licenses suspended. They Information Ministry officials said the editors are charged with offending the prophet of Islam and violating religions.

Earlier this month, two Jordanian editors were put on trial for reprinting the Danish caricatures of Muhammad.

Saudi Arabia's top cleric said in a Friday sermon that those responsible for the drawings should be put on trial and punished.

Muslims in several European and Asian countries, meanwhile, kept up their protests, with thousands taking to the streets in London's biggest demonstration over the issue so far.

Last week, demonstrators in tightly controlled Iran attacked the Danish, French and Austrian embassies with stones and firebombs and hit the British mission with rocks.

Iranian President Mahmoud Ahmadinejad, who is at odds with much of the international community over Iran's disputed nuclear program, launched an anti-Israeli campaign last fall when he said the Holocaust was a "myth" and that Israeli should be "wiped off the map."

In a speech marking the 27th anniversary of the Islamic Revolution Saturday, Ahmadinejad linked his public rage with Israel and the cartoons satirizing Islam's most revered figure.

"Now in the West insulting the prophet is allowed, but questioning the Holocaust is considered a crime," he said. "We ask, why do you insult the prophet? The response is that it is a matter of freedom, while in fact they (who insult the founder of Islam) are hostages of the Zionists. And the people of the U.S. and Europe should pay a heavy price for becoming hostages to Zionists."

The drawings — including one that depicts the prophet with a turban shaped like a bomb with a burning fuse — were first published in September and recently reprinted in other European publications that said it was an issue of freedom of speech.

Islam widely holds that representations of the prophet are banned for fear they could lead to idolatry.

Iran, a predominantly Shiite Muslim country, has seized on the caricatures as a means of rallying its people behind a government that is increasingly under fire from the West over its nuclear program.

Shiite Muslims do not ban representations of the prophet and some in Iran's provincial towns and villages even carry drawings said to be of Muhammad. But Tehran said the newspaper caricatures were insulting to all Muslims.

Austrian Foreign Minister Ursula Plassnik said on behalf of the European Union that Ahmadinejad's remarks should not be silently accepted.

"These remarks stand in complete contradiction to the efforts of numerous political and religious leaders who after the events of the past few days are campaigning for a dialogue between cultures that is marked by mutual respect," Plassnik said.

Plassnik was referring to appeals for calm made in recent days by Arab governments, Muslim clerics and newspaper columnists who fear the sometimes deadly violence has only increased anti-Islamic sentiment in the West.

Norway's ambassador to Saudi Arabia apologized on Saturday for the "offense" caused when a Norwegian newspaper published caricatures of the Prophet Muhammad.

Denmark, which has been stunned by the wave of protests over the caricatures that first appeared in the Danish newspaper Jyllands-Posten in September, urged its citizens on Saturday to leave Indonesia as soon as possible, saying they were facing "a significant and imminent danger" from an unnamed extremist group.

The warning came hours after the ministry said it withdrew Danish staff from Indonesia, Iran and Syria.

The Danish ambassador to Lebanon left last week after the embassy building in Beirut was burned by protesters.

Jyllands-Posten has apologized for offending Muslims but stood by its decision to print the drawings, citing freedom of speech.

The newspaper's culture editor, Flemming Rose, who was in charge of the drawings, went on indefinite leave Thursday, but many Muslims said that would do little to quell the uproar.

The paper has denied that Rose was ordered to go.

"He was not forced out," the paper's spokesman Tage Clausen told The Associated Press in Copenhagen. "He's on vacation, that's all."

Saudi Sheik Abdul Rahman al-Seedes, the imam of the Grand Mosque in Mecca, called on Muslims to reject apologies for the "slanderous" caricatures.

"Is there only freedom of expression when it involves insults to Muslims? he said in his sermon, which was published Saturday in the Al Riyad daily.

Noisy but peaceful rallies also were held in Turkey, Indonesia, the Netherlands, Germany, France, Switzerland and elsewhere, although the Middle East was largely calm.

Indonesian President Susilo Bambang Yudhoyono said the caricatures were damaging attempts to blend the Muslim faith with democracy.

"It sends a conflicting message to the Muslim community: that in a democracy it is permissible to offend Islam," the U.S.-educated leader wrote in a commentary that appeared Saturday in the International Herald Tribune.