Hundreds of U.S. military families are urged to leave southern Turkey amid new concerns about safety, a defense official said Thursday, September 3, according to Military Times.

The voluntary evacuation potentially affects about 900 people and comes after Turkey recently authorized U.S. combat aircraft to fly missions over Iraq and Syria from a key Turkish military installation.

"This decision was made out of an abundance of caution following the commencement of military operations out of Incirlik Air Base," said Pentagon spokesman Peter Cook.

The voluntary departure authorization is limited in scope to the Adana area near Incirlik; it does not apply to family members of military or civilian personnel in other cities, including Ankara, Istanbul and Izmir, Cook said.

"This is not being done because of any specific new threat. We've been at an elevated force protection level in Turkey, at Incirlik, for some time, now," he said.

About 1,800 U.S. troops are based at Incirlik. The military recently moved six F-16 combat jets to the base.