Turkish President Tayyip Erdogan is urging people to take to the streets to protest against what he described as a coup attempt by a minority faction within the military.
In a statement sent by email and reported on TV channels, the military said it had taken power to protect the democratic order and to maintain human rights.
All of Turkey’s existing foreign relations would be maintained and the rule of law would remain the priority, it said.
Airports were shut, access to Internet social media sites was cut off, and troops sealed off the two bridges over the Bosphorus in Istanbul, one of which was still lit up red, white and blue in solidarity with victims of the Bastille Day truck attack in Nice, France.
People in Ankara took to social media to post videos of low flying jets, or Turkish soldiers on the streets telling them to go home and that they had taken control.
Gunfire and an explosion were heard as warplanes and helicopters roared over the capital, Ankara.
Prime Minister Binali Yildirim said the elected government remained in office.
“Some people illegally undertook an illegal action outside of the chain of command,” he said in comments broadcast by private channel NTV.
“The government elected by the people remains in charge. This government will only go when the people say so.”
Those behind the attempted coup would pay the highest price, he added.
If successful, the overthrow of Mr Erdogan, who has ruled Turkey since 2003, would be one of the biggest shifts in power in the Middle East in years, transforming one of the most important US allies in the region.
Erdogan believes coup will be over in a ‘short time’
Mr Erdogan told a CNN Turk reporter via phone that Turkish people must gather in public squares to show their response to the attempted military takeover, in comments broadcast live on television.
Mr Erdogan said he believed the attempted coup would be over within a “short time” and said those responsible would pay a heavy price in the courts.
He said the act was encouraged by the “parallel structure” — his shorthand for followers of Fethullah Gulen, a US-based Muslim cleric who he has repeatedly accused of attempting to foment an uprising among his followers in the judiciary and the military.
The state-run Anadolu news agency said the chief of Turkey’s military staff was among people taken “hostage” in the capital Ankara. CNN Turk also reported that hostages were being held at the military headquarters.
TRT state television announced a countrywide curfew. An announcer read a statement on the orders of the military that accused the Government of eroding the democratic and secular rule of law.
The country would be run by a “peace council” that would ensure the safety of the population, the statement said.
Australia’s Department of Foreign Affairs updated its travel advice for Turkey, saying people should reconsider their need to travel to Istanbul and Ankara due to the attempted military action.
It warned Australians in those cities to follow directions of local authorities.
It’s not just a few colonels: Senior EU source
A senior EU source monitoring the situation said: “It looks like a relatively well orchestrated coup by a significant body of the military, not just a few colonels.
“They’ve got control of the airports and are expecting control over the TV station imminently. They control several strategic points in Istanbul.
“Given the scale of the operation, it is difficult to imagine they will stop short of prevailing. It’s not just a few colonels.”
One European diplomat was dining with the Turkish ambassador to a European capital when guests were interrupted by the pinging of urgent news on their mobile phones.
“This is clearly not some tinpot little coup. The Turkish ambassador was clearly shocked and is taking it very seriously,” the diplomat told Reuters as the dinner party broke up.
“However it looks in the morning, this will have massive implications for Turkey. This has not come out of nowhere.”
The military has a history of mounting coups to defend secular principles, but has not seized power directly since 1980.