Reporters Without Borders expressed concern after death threats were made against two cartoonists - whose names are being withheld for security reasons - after 12 cartoons of the prophet Mohammad appeared in the conservative daily Jyllands-Posten in Copenhagen. "It is unbelievable that one can make death threats against cartoonists in Denmark, one of the countries in the world that shows most respect for press freedom," said the worldwide press freedom organisation. One of the 12 cartoons, published on 30 September 2005, in Denmark's top-selling daily, with a circulation of 200,000, shows the head of Mohammed wearing a turban in the form of a bomb, the fuse of which is lit. All representation of the Prophet is banned by Islam. Jyllands-Posten published the series of cartoons to find out if cartoonists in Denmark were operating self-censorship. It made an appeal to cartoonists after a writer complained that nobody dared illustrate his book about the Prophet Mohammad. Twelve of them responded. The newspaper's editor, Carsten Juste, decided on 12 October to hire security staff to protect the journalists working for him after receiving several phone and emailed death threats following publication of "Faces of Mohammed". The two cartoonists against whom the threats were made have been forced into hiding. "It is shocking that they have been forced to hide for having published cartoons that caused offence," the worldwide press freedom organisation said. “No form of pressure or obstacle should force journalists into self-censorship, whatever subjects they choose." "We call on the interior Minister to open an investigation so that whoever is responsible for these threats can be punished as quickly as possible." A 17-year-old youth who was carrying a knife was arrested in connection with the case on 15 October in Aarhus, western Denmark. Muslim religious leaders in Denmark, who see the cartoons as an insult to Islam and to his prophet on 6 October called on the conservative daily to withdraw the cartoons and to make an official apology. Some 5,000 Muslims demonstrated in the streets of Copenhagen on 14 October, saying the cartoons were "provocative" and "arrogant". "We live in a democracy in which satire and caricature are generally accepted and religion should not try to put any limits on that," said Juste.