Among those detained were top military commanders, including the head of the Second Army, which protects the country’s borders with Syria, Iraq and Iran, state-run Anadolu news agency said.
Hundreds of soldiers were held in Ankara for alleged involvement in the coup, leaving police stations overflowing.
Some had to be taken under armed police escort in buses to a sports stadium. Reuters footage showed some of the detainees, hand-cuffed and stripped from the waist up, sitting on the floor of one of the buses.
The government declared the situation under control, saying 2,839 people had been rounded up, from foot soldiers to senior officers, including those who formed “the backbone” of the rebellion.