A media advocacy group is accusing Turkey of waging the "world's biggest crackdown" on media freedoms.

New York-based Committee to Protect Journalists said in a report released Monday that 76 journalists are in prison in Turkey and at least 61 of them are held because for "their published work or newsgathering activities."

The CPJ said journalists have been imprisoned on a "mass scale" on terrorism and anti-state charges. It accused the Turkish government of using "pressure tactics" to create an environment of self-censorship.

The group said Prime Minister Recep Tayyip Erdogan has pressured media groups to discipline or fire staff members, publicly deprecated journalists, and filed defamation lawsuits.

The government has rejected criticism that it seeks to muzzle opponents, insisting journalists are held for activity unrelated to journalism.