The issue of depicting the Prophet Muhammad
French magazine Charlie Hebdo has published a new cartoon of the Prophet Muhammad in its first issue since 12 people were killed during an attack on its offices in Paris by Islamist extremists who said they were "avenging the Prophet" after similar cartoons had appeared in the satirical publication.
The new cover depicts the Prophet Muhammad shedding a tear and holding up a sign saying "Je suis Charlie", the message of solidarity with the victims. Above the cartoon are the words "All is forgiven".
The move has drawn criticism from Muslim leaders and generated fresh death threats against staff members, recalling those received by a Danish newspaper in 2005 after it published cartoons satirising Muhammad.
Why might such depictions cause offence?
What does the Koran, the holy book of Islam, say?
There is no specific, or explicit ban in the Koran on images of Allah or the Prophet Muhammad - be they carved, painted or drawn.
However, chapter 42, verse 11 of the Koran does say: "[Allah is] the originator of the heavens and the earth... [there is] nothing like a likeness of Him."
This is taken by Muslims to mean that Allah cannot be captured in an image by human hand, such is his beauty and grandeur. To attempt such a thing is seen as an insult to Allah.
The same is believed to apply to Muhammad.
Chapter 21, verses 52-54 of the Koran read: "[Abraham] said to his father and his people: 'What are these images to whose worship you cleave?' They said: 'We found our fathers worshipping them.' He said: 'Certainly you have been, you and your fathers, in manifest error.'"
From this arises the Muslim belief that images can give rise to idolatry - that is to say an image, rather than the divine being it symbolises, can become the object of worship and veneration.
What does Islamic tradition say on the matter?
Islamic tradition or Hadith, the stories of the words and actions of Muhammad and his Companions, explicitly prohibits images of Allah, Muhammad and all the major prophets of the Christian and Jewish traditions.
More widely, Islamic tradition has discouraged the figurative depiction of living creatures, especially human beings. Islamic art has therefore tended to be abstract or decorative.
Shia Islamic tradition is far less strict on this ban. Reproductions of images of the Prophet, mainly produced in the 7th Century in Persian, can be found.
What sparked the row over cartoons published in Europe?
There were widespread protests across the Muslim world in 2005 after the Danish newspaper, Jyllands-Posten, published 12 cartoons showing Muhammad to accompany an editorial criticising self-censorship.
Some of the cartoons seemed to be deliberately provocative. One notably showed Muhammad carrying a lit bomb on his head decorated with the Muslim declaration of faith instead of a turban.
Many Muslims found the cartoons insulting an expression of a growing European hostility towards and fear of Muslims. The portrayal of the Prophet and Muslims in general as terrorists was seen as particularly offensive.
In 2011, Charlie Hebdo's office was firebombed after it temporarily renamed itself "Charia Hebdo" - a play on "Sharia", or Islamic law - for an issue and invited the Prophet Muhammad to be "editor in chief".
The next year, the magazine published an issue featuring several cartoons that appeared to depict Muhammad naked, amid a global uproar over the release of an anti-Islam film.