More than 100 people have been killed and 1,563 members of the armed forces arrested after an attempted military coup in Turkey.
Turkey's state news agency said almost 200 soldiers had surrendered at the military HQ.
Special troops have been sent in to secure the complex.
Turkey's chief of police, Celalettin Lekesiz, said 16 plotters were killed during clashes at the military police command.
The Anadolu news agency also reported that 1,154 people had been injured in the coup attempt.
Aerial attacks, explosions and gunfire ripped through Istanbul and the capital Ankara through the night.
Multiple blasts reportedly struck the parliament building in Ankara over the course of several hours, with lawmakers forced to retreat into shelters.
A military jet also dropped a bomb near the presidential palace in Ankara, according to a Turkish TV station, quoted by news agency AFP.
A military helicopter, apparently firing at the offices of the state satellite operator Turksat, was reportedly shot down.
At least three people were wounded when Turkey's intelligence agency headquarters were attacked by military helicopters and heavy machine gun fire, according to an intelligence source speaking to the Reuters news agency.
The source added that the agency's head, Hakan Fidan, was at a secure location and in constant contact with President Recep Tayyip Erdogan and Prime Minister Binali Yildirim.
A live television broadcast showed dozens of pro-coup soldiers who had seized Istanbul's Bosporus bridge abandoning their tanks with their hands in the air.
An email statement from the pro-coup faction insisted, however, that they were still "determinedly" fighting.
Earlier, Mr Erdogan, whose whereabouts were unknown for the first few hours of the coup, touched down in Istanbul to hundreds of cheering supporters.
In an address to the nation, he said he remained "at the helm", condemning the uprising as an act of "treason".
"This is a betrayal ... and they are going to pay for this," he said.
The president claimed his hotel on Turkey's Aegean coast was bombed after he left and that his general secretary, Hulusi Akar, was abducted by the coup makers. Mr Akar has since reportedly been rescued.
At one stage, Mr Erdogan conducted an extraordinary television interview, in which he addressed the nation from a mobile phone held up by the presenter.
The uprising began late on Friday with reports of the sound of gunfire and military fighter jets screeching through the skies of Istanbul and Ankara.
Soldiers then stormed Turkey's state broadcaster TRT, forcing a presenter to read a statement live on air announcing that the military had "fully seized control" of the country.
The statement said Turkey, a NATO member, was being run by a "peace council". It declared that martial law and a nationwide curfew were in place.
Nothing was initially heard from the Turkish president until an extraordinary television interview, in which he addressed the nation from a mobile phone held up by the presenter.
Among the first reported casualties were seventeen police officers killed in a helicopter attack on the police headquarters in the capital, according to Turkish news agency, Anadolu.
There were unconfirmed reports of explosions at Istanbul's Ataturk airport, forcing the cancellation or diversion of all commercial flights. Soldiers loyal to the government have since regained control of the airport, according to one Turkish official.
Blasts were also heard at Istanbul's famous Taksim Square, where large crowds gathered after news of the attempted coup broke
The well-being of a number of hostages, including a top general, who were reportedly taken at the military headquarters in Ankara remains unknown.
Meanwhile, Turkish television stations TRT and CNN Turk have both resumed broadcasting after being stormed by the military and briefly taken off the air.
It is unclear who is leading the movement. However, Mr Erdogan insisted some in the military have been taking orders from Fethullah Gulen, a US-based Turkish cleric who the president has repeatedly accused of fomenting unrest.
He said the attempted uprising was the work of a "parallel state" and "Pensylvania" - a reference to the state where the cleric is based.
Gulen's movement has denied involvement, saying in a statement that it was committed to democracy and was opposed to any military intervention
According to Turkish media, the military said it had taken action to: "reinstall the constitutional order, democracy, human rights and freedoms, to ensure that the rule of law once again reigns in the country, for the law and order to be reinstated".
The military statement said "all international agreements and commitments will remain. We pledge that good relations with all world countries will continue".
The Foreign Secretary, Boris Johnson, says he has spoken to his Turkish counterpart and underlined the UK's support for Turkey's democratically elected government.
The United States has issued a call for all parties in Turkey to support Recep Tayyip Erdogan's government against the coup attempt.
