A group of writers and artists from around the world penned a letter to Mexican President Enrique Peña Nieto, requesting he stop the violence against journalists in Mexico, Fox News Latino reported Monday. The letter was signed by over 500 journalists, writers, creative artists and free expression advocates from around the world.

The letter was posted on the website for the U.S. chapter of PEN International, an organization that promotes literature and freedom of expression. Famous British author Salman Rushdie, American author Paul Auster, Mexican film director Alfonso Cuaron and Nicaraguan writer Sergio Ramirez all signed the letter, which said, "with the support of PEN and the Committee to Protect Journalists (CPJ)," they wanted "to express our indignation regarding the deadly attacks against reporters in your country."

The letter refers to the recent deaths of photojournalist Ruben Espinosa and four women -- including human rights activist Nadia Vera -- who were murdered in Mexico City on July 31. Since 2010, roughly 41 journalists have been killed in Mexico, and around 20 have disappeared, according to the New York Times.

GettyImages-474462415 Mexican journalists and students of journalism take part in a demo about violence against journalists at the Angel de la Independencia monument in Mexico City, on Feb. 23, 2014. Photo: Getty Images

Many Mexican journalists are targeted by powerful criminal organizations and, in some cases, government officials. The letter demanded that Peña Nieto’s administration carry out a credible investigation into Espinosa’s death and closely examine local officials who may have been involved.

The letter stated that Espinosa’s slaying was, "only the latest in a long series of outrages against the press, and it took place in a city that was considered one of the last safe places in the country for reporters to work. There would now seem to be no safe haven for the profession.”

Statistics regarding impunity in crimes against the press are disastrous, the letter said, and cited that 89 percent of murders remain unsolved, according to the Human Rights Commission.