World Bulletin / News Desk
Seven military officers were arrested under an investigation into alleged coup plan known publicly as "Balyoz (Sledgehammer)", Anadolu news agency said.
The police had detained former heads of the air force and navy on Monday among 40 people held in the coup probes.
The swoop, one of the largest in the country against the armed forces, followed reports of several alleged plots in the past year.
The court in Istanbul ordered that four admirals, an army general and two staff colonels be jailed. It released six other officers Wednesday.
The court also ordered the officers to be jailed pending trial.
Prosecutors were still questioning dozens of other high-ranking officers, including former chiefs of the Navy, Air Force and Special Forces.
Top generals and admirals met at the military headquarters on Tuesday and issued a brief statement, saying they discussed "the serious situation" regarding the investigation.
The arrestees include Admiral Ramazan Cem Gundeniz, Admiral Aziz Cakmak, retired General Mehmet Kaya Varol, retired Admiral Ali Deniz Kutluk and retired Admiral Ozer Karabulut. They were sent to prison.
The detainees were questioned on suspicion of forming a group with the aim of overthrowing the government, according to the news channel.
News channels put the number at 49, including 17 retired generals, four serving admirals, 27 officers and one enlisted man.
According to previous media reports on the Sledgehammer plan, denied by the military, the army had plotted to provoke Greek fighter jets into shooting down a Turkish military jet and planned to plant bombs in mosques and museums in Istanbul to stir chaos.
Last month Taraf newspaper said it had obtained 5,000 pages of documents and tapes on the Sledgehammer plan, which was aimed at showing the AK Party was unable to protect the public and to justify an army takeover in 2003.
The military has said documents quoted by the paper were part of a military training seminar but were "never meant to be carried out and were not part of a conspiracy".
Other senior military officers have been indicted on charges of planning a separate plot to overthrow the AK Party.
The alleged criminal network that came to be known as "Ergenekon" was revealed after police seized 27 grenades, TNT explosives and fuses in a shanty house in Istanbul on June 12, 2007 and Istanbul Chief Prosecutor's Office launched an investigation into weapons.
Police waged several waves of operations in several provinces and detained dozens of people, including retired senior army officers, journalists, scholars and businessmen, for their alleged involvement in the network.
The 12th High Criminal Court which is hearing the case accepted three indictments with thousands of pages so far.
The culprits are charged with various crimes including attempting to overthrow the Turkish government with arms and acts of violence.