A Turkish court has ordered a former armed forces chief to be remanded in custody overnight pending trial over charges of planning to overthrow the government.
General Ilker Basbug is the highest ranking officer to be caught up in the so-called Ergenekon network, an ultra-nationalist group accused of conspiring against the government of Prime Minister Recep Tayyip Erdogan.
State prosecutors have been investigating allegations that Turkey's military launched websites to spread propaganda against Erdogan and his governing Justice and Development Party (AKP).
The former general was taken from an Istanbul courthouse in the early hours of Friday for a health check before being transported in a police convoy to Silivri prison, some 80km west of the city, where hundreds of defendants in the Ergenekon case are being tried in a specially built courtroom.
"The Republic of Turkey's 26th general chief of staff has been remanded in custody for forming and directing a terrorist group. I leave it to the great Turkish nation to judge," Basbug said as he was lead from the courtroom.
"We can say it is really tragicomic to accuse somebody who commands such an army of forming and directing a terrorist group," he was quoted as saying.
The decision to send Basbug to jail came hours after prominent Turkish journalists on trial over alleged ties to the ultra-nationalist Ergenekon network said the charges against them were politically motivated and "a massacre of justice" in a case that has raised concerns over media freedom in Turkey.
A protest has been staged against Basbug's arrest in the Turkish city of Istanbul, in which about 200 people marched through the centre of the city on Thursday.
The demonstrators accuse the government of trying to divide the country by targeting top military figures in the investigation over the alleged coup plot.
Basbug's lawyer said he would challenge the decision to jail him pending trial, state-run Anatolian news agency reported.
|Fadi Hakura, a Turkey expert, tells Al Jazeera that Basbug's arrest comes as no surprise
"The fact that prosecutors are now touching senior generals is a turning point in the democratisation process of Turkey. Many were sceptical that prosecutors would go this far," military affairs analyst Lale Kemal said.
"I would not be surprised if we see some commanders resign (if Basbug is remanded in custody) but I do not expect this to bring serious instability to Turkey," she said.
Turkish media reports this week suggested senior commanders could resign if Basbug was charged in the case.
The General Staff subsequently issued a statement denying those reports but speculation about possible resignations continued.
"There is every possibility there will be resignations if cases continue to be brought like this," security analyst Gareth Jenkins said.
"Morale is already at rock bottom. It is already affecting operational capability," he said.
Last July, Basbug's successor and the heads of the army, navy and air force resigned in protest at the detention of more than 200 officers charged in a separate alleged conspiracy against the government, dubbed "Operation Sledgehammer".
Investigations into Ergenekon have spiralled since they first opened in 2007, and critics accuse Erdogan's government of scaremongering to silence opponents. The government denies any such motives.
Several hundred suspects, including retired senior military officers, academics, lawyers and journalists, have been detained in cases related to it.
The Ergenekon case is seen as part of a power struggle between Erdogan's AK party, which has roots in a banned Islamist party and swept to power in 2002, and a secularist establishment including officers, lawyers, journalists and politicians.
Turkey is currently holding nearly 100 members of the media in jail, one of the highest numbers worldwide, in a crackdown that critics and rights groups say blights Muslim Turkey's image as a role model for democracy in the Middle East.
Late on Thursday, another court in Istanbul rejected a request from a prominent journalist to be released after nine months in custody on trial for links to the Ergenekon network.
"I am here because I am a journalist looking for the truth," said Ahmet Sik, who has written books about the infiltration of the police by an Islamist movement led by Fethullah Gulen, a Muslim theologian based in the US and considered close to parts of the ruling AK Party.