Updated

Nobel laureates and other writers have issued a message of solidarity to Turkish colleagues who have been jailed as part of what they call a "heavy-handed" crackdown against free expression.

Close to 150 writers and journalists are in prison in Turkey, several jailed as the government embarked on a massive clampdown on a network linked to a U.S.-based Muslim cleric blamed for Turkey's failed coup in July. The crackdown later extended to other government opponents.

Nobel laureates, including Elfriede Jelinek and J.M. Coetzee, and other high-profile authors vowed on Friday not to remain silent "while your human rights are violated."

"The writers of Turkey must be able to speak, to criticize, to protest without fear of reprisal," read the message issued as PEN International ended a mission to Turkey.