Turkish prosecutors are seeking jail terms of up to 43 years for 19 journalists and employees of opposition daily Cumhuriyet, the prosecutors said on Tuesday.

This comes as concerns over press freedom under Turkish President Recep Tayyip Erdogan are increasing.

The journalists are accused of being members of a banned “terrorist group” and aiding illegal organizations.

Most of the journalists have been in prison for the last five years.

Erdogan has announced that he will hold a referendum on April 16 in order to replace the country’s parliamentary system with the stronger presidency. The move has been strongly criticized by Erdogan’s opponents who fear a lurch toward authoritarianism.

Since a failed coup attempt last July, tens of thousands of people, from teachers and journalists to soldiers and police, have been detained by the Turkish government.

The Turkish government accuses Fethullah Gulen, a US-based cleric, of orchestrating the failed coup. The prosecutors also accuse Cumhuriyet of being under the control of Gulen.

Erdogan’s opponents say he has used the state of emergency to crack down on all forms of opposition, while Turkish authorities insist that those who have been imprisoned are charged with crimes and the charges have nothing to do with their journalism.