A spokesperson for the Association of British Travel Agents said: "Media reports suggest that a Military Coup may be taking place in Turkey".
Chaos reigns across Turkey overnight amid reports of aerial dogfights and bombings, military blockades and clashes between mobs and armed forces.
Mr Erdogan called his supporters out onto the streets, and in several locations they outnumbered putsch soldiers.
Turkey's armed forces are determined to remove members of the "parallel structure" from their ranks, the military's acting chief of staff said on Saturday. Authorities arrested thousands of people as President Recep Tayyip Erdogan vowed those responsible "will pay a heavy price for their treason to Turkey". "Turkey has irreversibly closed the chapter of military coups".
More than 2,800 military were detained after the military coup attempt in Turkey, Binali Yildirim said.
Gunfire and explosions had rocked both the main city Istanbul and capital Ankara in a chaotic night after soldiers took up positions in both cities and ordered state television to read out a statement declaring they had taken power.
The coup attempt was also condemned by the country's four major parties represented in the Turkish parliament - including the three parties in opposition.
Arriving in Istanbul hours later, the president said he would not leave Atatürk Airport until the situation in the country returns to normal.
In a statement, the Turkish foreign ministry said the coup attempt "was foiled by the Turkish people in unity and solidarity". American jets use its Incirlik air base to fly missions against the extremists in Syria and Iraq.
It later shuts down key bridges, takes control of Istanbul's Ataturk worldwide airport and issues a curfew. This government, brought to power by the people, is in charge.
Eurasian leaders, attending a July 15-16 summit about economic cooperation and regional connectivity, has been distracted by twin incidents in the last two days - the Turkey crisis and the terror attack in French city of Nice late Thursday that killed 84 people.
Erdogan told CNN Turk he didnt believe the coup would succeed, adding: There is absolutely no chain of command here. We say democracy over hypocrisy. Fighter jets under the control of loyalist forces were flying over the capital to strike at helicopters flown by coup supporters, the Anadolu news agency said.