By Gulsen Solaker
ANKARA (Reuters) - Two jailed Turkish editors, accused of spying and helping a terrorist group, have told Reuters in a faxed message from prison that their arrest was designed to send a warning to journalists.
Can Dundar, editor-in-chief of the left-wing Cumhuriyet newspaper, and its senior editor Erdem Gul were arrested on Nov. 26 over the publication of footage purporting to show the state intelligence agency helping send weapons to Syria.
The issue of Turkey's involvement in Syria is particularly sensitive as the NATO member comes under pressure to take a more active role in the fight against Islamic State militants there. President Tayyip Erdogan has cast the newspaper's coverage as part of a bid to undermine Turkey's standing on the world stage.
"Our arrest is a clear message aimed at the press, saying: 'Don't write.' This is a direct drive at self-censorship," the two journalists said in a handwritten fax, cleared by a prison committee that reads inmates' correspondence.
A senior government official denied there was any political agenda behind the investigation and said it was purely a legal matter. "There is an open breach of law. Such criticism of the government is unacceptable," the official said.
The detention of the two journalists sparked protests in Turkey as well as condemnation from U.S. and European Union officials, concerned that Erdogan and the government are silencing critical voices and exerting too much influence over courts after winning an outright majority in a Nov. 1 election.
Erdogan is a vital partner for both Washington and the EU in efforts to combat Islamic State, end Syria's civil war and curb the flow of migrants and refugees to Europe, all factors that may prompt foreign governments to pull their punches over his human rights record.
Gul and Dundar, who is also a popular documentary filmmaker, are accused of espionage and aiding a terrorist group. They insist their arrest had no legal basis.
Cumhuriyet, one of Turkey's oldest newspapers and affiliated with parliament's secular opposition, published photos, videos and a story in May which it said showed intelligence officials transporting arms to Syria in trucks, allegedly to opposition fighters.
Erdogan has said the trucks, which were stopped that day by soldiers near the city of Adana en route to the Syrian border, belonged to the intelligence agency. He has said prosecutors had no authority to order the trucks be searched, and that they acted as part of a plot to discredit the Turkish government.
At the time, he vowed Cumhuriyet "would pay a heavy price. I won't let go of this."
Prime Minister Ahmet Davutoglu, who succeeded Erdogan as leader of the governing AK Party, has said a court should try Dundar and Gul for threatening Turkey's strategic interests but that they should not be jailed ahead of that trial.
However, they remain in prison some 80 km (50 miles) west of Istanbul, with no indictment or trial date set.
"In a country with imprisoned journalists, the media is already under heavy pressure to self-censor. This ... poses a mortal danger for the whole country," the pair said in their faxed statement, dated Jan. 10, in response to written questions from Reuters submitted through their lawyer.
The fax was signed by Gul, but the lawyer, Tora Pekin, said he had written on behalf of both journalists. The delay in receiving the response was due to prison rules that allow inmates to send faxes only three days a week, Pekin said.
Turkey has about a dozen journalists serving sentences or in pre-trial detention. According to the New York-based Committee to Protect Journalists, only China, Egypt, Iran and Eritrea have more.
They are mostly leftists, Kurds or members of a religious order led by Fethullah Gulen, a U.S.-based preacher sought by police on terrorism charges in connection with stories his followers ran in papers and TV channels close to the movement.
The government says they are all in prison for promoting terrorism or engaging in anti-state activities rather than simply for their journalistic work. Erdogan said in 2014 Turkey has the "world's freest press" because it tolerates insults, defamation and racism, including against him and his family.
The two editors were held in solitary confinement for 40 days before being moved to the same prison ward, they said.
"Because we think our arrests are not legal but political, it is difficult to guess how long it will last. Our arrests are in themselves a violation of the current law."
Their lawyer said the Justice Ministry has blocked applications by more than 100 journalists, as well as foreign officials and non-governmental organizations, to visit them.
Only their lawyers, family members and lawmakers are allowed to see the men. Government officials say their detention is a matter for the judiciary, not a political affair, and that as such they cannot intervene.
(Writing by Ayla Jean Yackley; Editing by Nick Tattersall and Mark Trevelyan)