Turkey President Recep Tayyip Erdoğan was greeted by large crowds at Istanbul's main airport early Saturday, as forces loyal to him battled to fend off a military coup that left at least 42 reported killed and dozens more injured.
In a press conference at Ataturk Airport, Erdoğan said the architects of the coup attempt would "pay a heavy price" and vowed he would "not surrender this country to intruders."
Prime Minister Binali Yildirim, speaking to state-run Anadolu Agency, said more than 120 arrests had been made.
Despite claims by multiple Turkish government officials that the takeover attempt had been repelled, reports of ongoing violence indicated that authorities did not have full control of the situation.
The Ankara prosecutor's office said at least 42 people had been killed in "attacks" in the capital. At least 17 of the victims were police officers killed in a helicopter attack on police special forces headquarters in Ankara. An official at Haydarpasa Numune Hospital in the Uskudar district of Istanbul told The Associated Press they had admitted at least 150 wounded, but declined to comment on whether there had been any fatalities.
Despite stating that the plotters were "a minority within the military," Erdoğan also admitted that his general secretary was abducted by coup makers and that he did not know the whereabouts of the chief of the military staff. The president also said that his vacation residence in the holiday resort of Marmaris had been bombed earlier that evening.
A Turkish lawmaker contacted by Reuters said he and his colleagues were hiding in special shelters in the bowels of the parliament building after at least three explosions near the complex in the capital, Ankara. Parliament Speaker Ismail Kahraman told the Associated Press a bomb hit one corner of a public relations building inside the parliament complex, injuring some police officers.
Elsewhere, troops also fired in the air to disperse a growing crowd of government supporters at the Taksim monument in Istanbul as military helicopters flew overhead. A nearby mosque made an anti-coup announcement over its loudspeakers.
A Turkish government spokesman confirmed that an F-16 fighter had shot down a helicopter that had been commandeered by soldiers supporting the coup. Anadolou reported that military helicopters also attacked the headquarters of TURKSAT satellite station on the outskirts of Ankara.
CNN Turk reported that soldiers had entered its offices in Istanbul and cut off its broadcast. An anchor said, "We must abandon the studio, we tried to broadcast everything until the last minute... and I am being asked to leave the studio." A camera showed an empty anchor desk as chants of "Soldiers out!" could be heard inside and outside the studio. The channel later resumed normal programming.
Earlier, the state-run television broadcaster TRT was similarly knocked off the air, but later came back online.
In his TV address, Erdoğan blamed the attack on supporters of Fethullah Gulen.
Erdoğan has long accused the cleric and his supporters of attempting to overthrow the government. The cleric lives in exile in Pennsylvania and promotes a philosophy that blends a mystical form of Islam with staunch advocacy of democracy, education, science and interfaith dialogue.
Speaking by cell phone to CNN Turk from an unknown location in the early hours of the coup, Erdoğan vowed that Turkey would "overcome this invasion" and called on Turks to "gather in squares and see what this minority can do with their tanks and artillery against the people."
Ordinary Turkish citizens appeared to heed Erdoğan's call, as TV footage showed marching through the streets of Izmir and Istanbul waving Turkish flags. Crowds also gathered in Ankara's main square.
"Throughout history those who make coups have been unsuccessful, and I absolutely believe that these will be unsuccessful as well," Erdoğan said.
In Washington, a statement from the White House said President Barack Obama and Secretary of State John Kerry agreed that both sides "should support the democratically elected government of Turkey, show restraint and avoid any violence or bloodshed."
A senior Defense Department official told Fox News that the unrest was having "no impact" on anti-ISIS missions flown out of Incirlik Air Base in southeastern Turkey.
NATO Secretary General Jens Stoltenberg issued a statement calling for "calm and restraint, and full respect for Turkey's democratic institutions and its constitution."
The coup began shortly before 11 p.m. local time Friday, when gunshots were first reported in Ankara. As military helicopters flew over the entertainment hub of Beyoglu district in Istanbul, televisions aired footage of military tanks and TV stations reported Turkish state TV had been taken over by military officials.
A military statement read on Turkish state TV announced that martial law had been imposed across the country and a curfew had been declared. The statement added that Turkey was now being run by a "peace council" and that a new constitution would be drawn up soon.
However, some senior military leaders refused to back the coup attempt, appearing on television to denounce the plotters and urge soldiers back to their barracks.
"Those who are attempting a coup will not succeed. Our people should know that we will overcome this," Gen. Zekai Aksakalli, the commander of the military special forces, told the private NTV television by telephone.
Prime Minister Binali Yildirim admitted to Haberturk TV that an "attempt" had been made against the government and warned "those who carry out this attempt will be subjected to heaviest punishment."
Turkey's Justice Minister Bekir Bozdag also spoke on national TV, calling on "everyone to raise their voices against this attempt by the military and to embrace democracy."
Soldiers and military vehicles also blocked one-way traffic on the Bosporus and Fatih Sultan Mehmet bridges in Istanbul, which link the continents of Europe and Asia.
As the crisis unfolded, there were reports that access to popular social media sites like Twitter and Facebook had been blocked within the country. Facebook declined comment, but Twitter said it suspected "intentional" interference with its service.
The chaos capped a period of political turmoil in Turkey blamed on Erdoğan's increasingly authoritarian rule, which has included a government shake up, a crackdown on dissidents and opposition media and renewed conflict in the mainly Kurdish areas of the southeast.