Communist Yugoslavia's only official human rights monitoring body has appealed for all prisoners convicted of "verbal offenses" to be set free, official Belgrade newspapers said on Wednesday.

More than 500 Yugoslavs are jailed for political crimes every year, according to official figures. But the total number of political prisoners in Yugoslavia is not available.The majority are jailed under article 133 of the Penal Code, known as the "verbal delict" law, a catch-all curb on freedoms to criticize the state or politicians or to voice unorthodox political views either orally or in writing.