President Erdogan calls on people to defeat military coup
Calls have been made from mosques for people to go onto the streets and support the government, as thousands took massed in public areas of Istanbul.
There were reports that 17 police officers had been killed in the coup attempt, while a police station in Ankara was fired on by a military helicopter.
AFP also reported that a helicopter carry coup plotters had been shot down by a Turkish military war plane.
Back in public
The president who had reportedly gone into hiding, made a defiant public appearance and vowed that "coup plotters" would not succeed in the attempted takeover.
He called on people to take to streets to support the government and the democratic system, after a military group announced a power grab.
All main parties have announced their opposition to the coup and backing for the Turkish government.
"I certainly believe that coup plotters will not succeed," Erdogan told CNN Turk television, speaking on FaceTime via mobile phone.
"I urge the Turkish people to convene at public squares and airports. I never believed in a power higher than the power of the people."
Erdogan said he was still president and Turkey's commander in chief, promising that plotters would pay a "very heavy price".
A presidential source said Erdogan was in a secure location as per government protocol.
Agencies contributed to this report.