Turkish authorities have re-arrested a four-star general over an alleged plot to overthrow the Islamist-rooted government, state-run news agency Anatolian said on Friday. Cetin Dogan, former head of Turkey's prestigious First Army, was one of the most senior figures to be charged during a wave of military detentions in February which revived tension between the government and armed forces, the self-appointed guardians of Turkey's secularism. Dogan spent a month in custody before being released at the start of April pending trial. Prosecutors then ordered his re-arrest, although this was delayed to allow him to have treatment for a hernia in hospital. Scores of officers have been detained and charged over the alleged “Sledgehammer” plot. Some were later freed on bail and others re-arrested. Turkey's military, which is the second largest in NATO, says there is no conspiracy and Operation Sledgehammer was merely a war game exercise presented at a seminar. The operation involved bombing mosques and provoking Greece into shooting down a Turkish war plane to create a war-like situation and destabilise the government. Few analysts believe the army would launch a coup, although it has overthrown three governments since 1960, and pressured Turkey's first Islamist-led government into resignation in 1997.