A retired Turkish general charged over a plot to unseat the government said "the struggle has now started", as a string of high-profile arrests risks renewed strain between Ankara and the military.
Two former generals, the most senior figures arrested so far over an alleged 2003 plot, were charged late on Friday and taken to prison on remand, state-run news agency Anatolian reported.
Hours earlier, police had conducted a second wave of military detentions, widening an investigation that has seen some 33 officers arrested, prompted an emergency summit among Turkey's leaders and shaken Turkish markets.
Retired general Cetin Dogan was the former head of Turkey's First Army and as such had occupied a position often seen as a step towards becoming head of the Turkish Armed Forces.
"When Dogan learned he was to be charged he said 'the fight has started now'," his lawyer Celal Ulgen said on Saturday, according to Anatolian.
Ulgen added there was no concrete evidence and prosectors went to great lengths to have him charged.
The other high-ranking official to be charged was Lieutenant-General Engin Alan, a former special forces commander who led a successful operation to capture the country's most wanted man, Kurdish separatist leader Abdullah Ocalan, and bring him back to Turkey in 1999.
Turkish newspapers on Saturday printed pictures of an elderly-looking Dogan, dressed in a dark coat and cravat and walking with a slight stoop, as police took him for questioning.
Turkish markets, weakened by five days of tension since a first wave of detentions on Monday, had begun to recover on Friday on hopes that the likelihood of a confrontation between the government, in power since 2002, and the secularist military was receding with the release of three other retired generals.
But reports police had detained 17 more serving military officers and one retired officer sparked renewed selling, and fresh concern over a possible standoff.
"The second wave of arrests will have already raised the tensions," said Istanbul-based analyst Gareth Jenkins, ahead of news of the retired generals' arrest. Should the pair be charged and held on remand this could up the stakes even more, he said.
Prime Minister Tayyip Erdogan has accused the media of fanning alarm among investors, who were unnerved by a first wave of detentions on Monday of some 50 officers over the plot.
Erdogan's party, which denies accusations it has a secret Islamist agenda, is banking on an economic recovery to win over voters ahead of an election due early next year.
ON EDGE, NOT PANICKY
The military has overthrown four governments in Turkey in the past 50 years and with some of its officers still in detention, and more than 30 charged, markets remain nervous.
Investigations of the three released commanders continue.
"Dogan, the former commander of the First Army where the alleged 2003 coup plan is said to have been drafted, was a key player in the campaign that in 1997 ousted from power the Islamist Welfare Party led by Erdogan's mentor, Necmettin Erbakan," said Wolfango Piccoli, Eurasia Group analyst.
The Turkish military forced Erbakan's government from power with a series of threats and demands. Erdogan was the Welfare Party's vocal mayor of Istanbul at the time. Secularists suspect Erdogan and his party of trying to Islamicise the state by stealth; filling the bureaucracy and judiciary with supporters.
Despite Turkey's history of military coups and interventions in politics, most people believe the generals would not dare challenge the AK Party, which has a huge parliamentary majority, and destroy newfound confidence in democracy.
Turkey is a NATO member and EU membership candidate, and its Western allies want to see it mature as a democracy.
Analysts fear politics appear increasingly polarised between the secular, conservative nationalists who represent the old guard and the AK Party, which has won over investors with market-friendly reforms despite its roots in political Islam.
While markets have been edgy, investors have not hit any panic buttons since trouble first erupted last week between the government and the judiciary, another secularist bastion.