(REUTERS) - Airlines diverted flights en route to Turkey and cancelled departures from Istanbul's Ataturk Airport as a coup attempt unfolded in the country on Friday, pitting Turkey's military against supporters of President Tayyip Erdogan.
A Reuters witness heard a loud explosion at Ataturk Airport. Television images showed tanks parked in front, while scores of people gathered in Istanbul and capital city Ankara to show their support for the elected government.
Government officials insisted that a small group within the military was behind the attempted coup, while the army officials claimed to have seized power. "My Family are stuck in Istanbul airport and have no idea what is happening," Twitter user Fatti (@Rubynapanahi) said."What is going on with the world." Cynthia Wee (@Its-A-Cyn) said, "many stranded at airport #help," noting in another post that her family was scared.
European air traffic control agency Eurocontrol said all flights arriving at Ataturk Airport were being diverted.
Flight tracking website FlightAware.com so far listed 138 cancelled departures for Friday and Saturday.
The crisis follows a series of bombings that have hit Turkey this year, including a suicide attack in June that killed 45 people at Istanbul's main airport. They have weighed on international travel to the country.
A British Airways flight to Istanbul on Friday night diverted to Sofia, Bulgaria, and a Lufthansa flight to Istanbul returned to its origin in Frankfurt, company spokeswomen told Reuters.
The US Federal Aviation Administration said all U.S.-bound flights from Istanbul that were in the air prior to the airport's closing would be allowed to land in the United States as planned. Turkish Airlines did not immediately comment.
With reports of gunfire in the streets, governments from the United States to the United Kingdom and Mexico called on their citizens in Turkey to seek shelter. "Things will be fluid for some time and all people can do is wait it out," said Bruce McIndoe, chief executive of travel risk consultancy iJET. McIndoe said his firm had received calls from clients and their employees based in Turkey for advice.
As of July 2, international flight bookings to Istanbul for trips in the second half of the year were down 36 percent from a year ago, travel data analysis company ForwardKeys said on its website.
Arrivals from the Americas and Asia-Pacific were down 45 percent, according to ForwardKeys. In the past six months, bombings in Istanbul led to progressively sharper declines in bookings, it said.