Flights from Istanbul airport to Tehran were cancelled on Friday night amid a mounting US military buildup around Iran.
Istanbul airport said flights by Turkish Airlines and two Iranian companies to the Iranian capital had been cancelled.
Four flights to Tehran scheduled for Saturday were also cancelled, though six others remained on the schedule. A Turkish Airlines flight to the northern Iranian city of Tabriz, due to leave early Saturday, was called off.
Turkish authorities made no comment on events in Iran on Friday, declining to join the litany of nations advising their citizens against travel to the Islamic republic.
Turkey has a 550 kilometre (340 mile) frontier with Iran that has three crossing points.
