Some 200 leading writers appealed Friday to China to respect freedom of expression and free jailed authors, describing the country’s strict censorship as a stain on a vibrant culture.

In an open letter issued on International Press Freedom Day, the writers celebrated the growing recognition of China’s artists, pointing to the Nobel Prize for Literature won last year by Mo Yan.

“We cannot, however, listen to China’s great and emerging creative voices without hearing the silence of those whose voices are forcibly restrained,” they wrote.

“We cannot appreciate the accomplishments of Chinese creators across disciplines without thinking of the works we are not able to enjoy because of censorship in the arts, in the press and on the Internet — or of the many other works that cannot be imagined or created because of these constraints.”

They appealed for China to release more than 40 writers or journalists from prison, including Liu Xiaobo, the author of a bold petition for democratic reform who won the Nobel Peace Prize in 2010.

The 195 signatories included Nobel laureates J.M. Coetzee, Nadine Gordimer, Wole Soyinka, Tomas Transtromer and Mario Vargas Llosa. The letter was released by Pen International, a literary group that promotes freedom of expression.

In an accompanying report, Pen International urged China to end censorship of the Internet, lift travel bans and restrictions on writers with different views, and ensure linguistic rights of ethnic minorities.

“There is nothing shocking, there is nothing surprising, about them. We’re talking about very basic things. These are fair and realistic recommendations,” John Ralston Saul, president of Pen International, told a news conference.

Salman Rushdie, who spent a decade in hiding after Iranian leader Ruhollah Khomeini ordered his death for the novel “The Satanic Verses,” said he heard an “unusually eloquent” phrase by an Iranian ayatollah on Internet censorship.

“He said that it was like removing a ladder to stop birds from sitting on the roof,” Rushdie said.

The Pen International report said that as many as 50,000 people work for China’s “Internet police” to trawl online and censor content deemed offensive.

“It increases in force; there are more and more people every year doing this,” Rushdie said. “Even in that case, removing the ladder is not preventing birds from sitting on the roof.”