Cartoons of the Prophet Muhammad published in several European newspapers have caused outrage among some Muslims. The BBC News website looks at the key questions behind the row. How did the row develop?
The cartoons were first published in September 2005 by Danish newspaper Jyllands-Posten. They were later republished in Austria in January, and then at the beginning of February in a number of European newspapers in France, Germany, Italy and Spain.
Diplomatic protests by governments of Islamic countries started in October 2005, escalating to the closure of embassies.
Boycotts of Danish products and protests across the Islamic world built up in late January and early February. In the Palestinian territories, armed groups have made direct threats against citizens of the countries in which the cartoons were published. There have also been death threats against the artists.
On 2 February, Danish Prime Minister Anders Fogh Rasmussen appeared on Arabic TV to apologise for offence caused by the cartoons, but he also defended freedom of expression.
There have since been angry and sometimes violent protests across the Islamic world, and in Britain and France.
What do Muslims say about the cartoons?
Many Muslims say that the cartoons - one of which shows Muhammad wearing a bomb-shaped turban - are extremely and deliberately offensive, expressing a growing European hostility towards and fear of Muslims. The portrayal of the Prophet Muhammad and Muslims in general as terrorists is seen as particularly offensive.
Some Muslims see the cartoons as an attack on their faith and culture designed to sow hatred.
Islamic tradition explicitly prohibits images of Allah, Muhammad and all the major figures of the Christian and Jewish traditions.
Has Muslim reaction to the cartoons been uniform?
Not at all - some Muslims have accused protesters of overreacting.
A weekly newspaper in Jordan reprinted some of the cartoons and urged Muslims to "be reasonable".
Websites produced by and for Muslims have shown the cartoons or linked to them. One liberal website said Muslims were making a mountain out of a molehill.
Some Muslims, mainly in Europe, have supported the re-publication of the images so that individual Muslims can make their own minds up and welcomed the debate on the issues that that cartoons have raised.
It has also been pointed out that cartoons in the Arab and Islamic press "demonising" Jews and Israelis are common.
Why did the Danish newspaper publish the cartoons?
The Danish newspaper that originally published the cartoons commissioned them after the author of a book about Islam said he was unable to find a single person willing to provide images of the Prophet.
The newspaper's culture editor, Flemming Rose, says he did not ask the illustrators to draw satirical caricatures of Muhammad. He asked them to draw the Prophet as they saw him.
Rose has insisted that there is a long Danish tradition of biting satire with no taboos, and that Muhammad and Islam are being treated no differently to other religions.
He also argues that the images have raised the profile in Denmark of a debate on integration of religious minorities.
The newspaper editors who have republished the cartoons say they are defending the right to free speech and acting in solidarity with the Danish newspaper, Jyllands-Posten.
What are the issues raised by the cartoons?
In many European countries there is a strong sense of secular values being under fire from conservative Islamic traditions among immigrant communities. Many commentators see the cartoons as a response to this.
There are also issues of integration - how much should the host society compromise to accommodate immigrant populations, and how much should immigrants integrate into the society they are making home.
Some commentators have defended the cartoons, saying they address fault lines in changing European societies that need to be discussed more openly.
Has anything like this happened before?
Culture clashes of this kind are not new.
In 1989 Iran's spiritual leader Ayatollah Khomeini called on Muslims to kill British author Salman Rushdie for alleged blasphemy in his book The Satanic Verses.
This may be closest comparison to the current situation. It raised many of the same issues - sensitivity of host cultures to religious sensibilities, integration of immigrants, religious intolerance and freedom of speech.
It took many years for the controversy over Mr Rushdie's novel to fade away, and for the author to emerge from hiding
(BBC News)