The attempted coup by a section of Turkey's military was an act of treason and is a reason to "clean up" the armed forces, Turkish President Tayyip Erdogan said on early on Saturday, hours after the armed forces attempted to overthrow him.
The Associated Press contributed content to this report.
Bombs were thrown at the Parliament building in the capital Ankara. An official at Istanbul's Sisli Hamidiye Etfal Training and Research Hospital said they had also received dead and wounded. Prime Minister Binali Yildirim however told Turkey's NTV news channel that Ankara airspace is closed.
The upheaval began Friday evening when tanks and other armored vehicles appeared on bridges across the Bosporous in Istanbul and F-16s began streaking through the skies.
Turks took to the streets of cities across the country waving national flags throughout the attempted coup to show their support for the government.
Fighter jets under the control of loyalist forces were flying over the capital to strike at helicopters flown by coup supporters, the state-run Anadolu news agency said. "We pledge that good relations with all world countries will continue", the military said in the unnamed statement.
A man covered with blood points at the Bosphorus Bridge as Turkish military members clash with people at the entrance to the bridge in Istanbul on Saturday. Kerry said he urged all parties to ensure the safety and well-being of diplomatic missions, personnel and civilians across Turkey.
Television images showed tanks gathering at Istanbul's Ataturk Airport, the country's largest.
First Army commander Umit Dundar said that the coup-plotters represent a small minority in First Army command.
The president's office would not reveal Erdogan's whereabouts, saying only that he is at a secure location.
Turkey has a history of coups, with governments ousted on three occasions by full military coups since 1960.
The tanks and troops deployed earlier to Istanbul's Ataturk Airport have been withdrawn, allowing police and hundreds of Erdogan supporters to enter the terminal.
"Some people illegally undertook an illegal action outside of the chain of command", Yildirim said in comments broadcast by private channel NTV.
He blamed the coup on "parts" of the military, and said security forces will "retaliate in kind", according to reports.
Military jets were heard flying over the Turkish capital earlier, and several checkpoints had been set up around the city as well as Istanbul, according to witnesses. The military has taken over the government and imposed martial law, according to an announcement made on the Turkish state broadcaster TRT.
"I don't think Erdogan would be calling for citizens to come out on the streets if he felt that he had the upper hand in defeating the coup", George Petrolekas, a fellow with the Canadian Global Affairs Institute, said in an email to Global News. Media reports said ambulances were seen in front of the Turkish military headquarters.
"Those who are responsible, we will give them the necessary punishment", Erdogan said.
In a statement sent to media, the group said: "We condemn any military intervention in domestic politics of Turkey". The Dogan news agency reported that soldiers fired on a group of people trying to cross the Bosporus bridge to protest the attempted coup, and that some people have been hurt. Yildirim vowed the coup attempt would not succeed.
Facebook and Twitter were reportedly blocked in March after pictures from a deadly auto bombing spread on social media.
The State Department and U.S. Embassy in Ankara also warned Americans in country to be vigilant and shelter in place.