ISTANBUL (AP) -- About 40 prominent academics and authors from around the world are urging Turkey’s government to end what they say is the persecution of the country’s own writers and professors voicing differing points of view.

In an open letter released Sunday, academics and authors including Turkish Nobel laureate Orhan Pamuk and British Booker Prize winner John Berger called on supporters to protest what they said is the Turkish government’s “vendetta” against its brightest thinkers.

They said the failed July 15 coup shouldn't be used as a pretext for a “McCarthy-style witch hunt.”

They said particularly disturbing was the detention of novelist Ahmet Altan and his brother Mehmet Altan, an economics professor, for allegedly transmitting subliminal messages to rally coup supporters on TV shown the night before the coup attempt.