A Turkish court on Tuesday upheld prison sentences against seven journalists from the opposition newspaper Cumhuriyet, ordering them to be sent to jail, according to sources close to the case.

The journalists were arrested over alleged ties to the outlawed Kurdistan Workers' Party (PKK) and the Gulen Movement, an international Islamist movement founded by Fethullah Gulen, an exiled preacher who, the Turkish government alleges, masterminded a failed coup carried out in the Middle Eastern country in July 2016, something Gulen and his supporters deny.

"Nothing was legal. Everything in our trial was political. To hope otherwise would be to dream. I will have to spend a year and a month in jail," Guray Oz, one of the sentenced journalists, told EFE over the phone.

Despite being in pretrial detention for six months, the seven journalists are set to serve over a year in jail as the pretrial time they have served did not take effect due to the legal appeals process.

A source connected to the case told EFE the jail sentences could only be appealed at the Constitutional Court in Turkey.

The court ruling sparked criticism from human rights organizations and journalists unions.

In total, 19 journalists from Cumhuriyet, the country's oldest newspaper, have been on trial for alleged links to terror groups.

"This was a political trial from Day 1, this decision should be overturned! #JournalismIsNotACrime #FreeTurkeyMedia," Reporters Without Borders (RSF) tweeted.

Meanwhile, the International Press Institute said: "We condemn this decision to uphold arbitrary, politically motivated convictions."

According to state-run news agency Anadolu on Tuesday, Turkey has issued arrest warrants against 281 people over alleged links to Gulen.

Gulen, who from 2002-2013 was an ally of Turkey's President Recep Tayyip Erdogan, currently lives in exile in the United States.

The movement that began to grow up around Gulen in the city of Izmir in the 1970s quickly spread across Turkey via a private Islamist school network which then morphed into an international private school network.

The Gulen movement, through organizations based in separate states in the United States, owns and controls many charter schools.

Turkey has jailed dozens of journalists and shut down several media groups linked with the movement since the coup attempt on July 15, 2016.

Tens of thousands of public workers, soldiers and police, as well as other state institution employees, have been arrested or fired over suspected ties to the movement since the failed coup.