The United States has ordered the families of diplomats and military people to leave parts of Turkey due to security fears.
After a series of deadly blasts in major Turkish cities, the US European Command says, while the order is not permanent, it is intended to "mitigate risk."
The latest move comes as Israel is warning its citizens to leave Turkey for security reasons, too.
Once a beacon of stability in the region, Turkey has entered a period of high tension and violence.
A spate of deadly bombings has struck key cities as Turkey struggles to fend off Kurdish militants in its restive east and monitor violence and displacement in neighbouring Syria.
Now, the United States has ordered the families of its military, diplomatic and other government people to leave the city of Adana in southern Turkey.
That includes the Incirlik air base, used heavily in the fight against the self-proclaimed Islamic State.
US Pentagon spokesman Peter Cook says Department of Defence families have also been told to leave Izmir and Mugla provinces.
"This decision allows for the deliberate safe return of family members from these areas, due to continued security concerns in the region. It in no way signifies a permanent decision to end accompanied tours at these facilities and is specifically intended to mitigate the risk to DOD elements and personnel, including family members, while ensuring the combat effectiveness of US forces and our support mission to operations in Turkey."
About 5,000 Americans had been staying at the Incirlik air base.
Last year, security fears prompted officials to ban soldiers and their families from visiting markets and restaurants that have flourished outside the base's main gates.
Soon, military families were offered the chance to evacuate voluntarily, but, now, they are being ordered to leave.
The Pentagon says there was no specific threat that triggered the decision.
But based on what has been happening in the region, the Pentagon is exercising what it calls an "abundance of caution."
US State Department spokesman John Kirby insists it is not related to this week's nuclear security summit in Washington that Turkish president Recep Tayyip Erdogan will attend.
"Absolutely no connection to that whatsoever. This was done, as it should be, based on the security threat and our concern about the safety for American citizens, whether they're government employees or not -- in south-eastern Turkey, in particular."
The State Department has also reissued a travel warning, advising tourists of what it calls "increased threats from terrorist groups throughout Turkey."
It warns them to avoid travelling to the country's south-east.
On the streets of Istanbul, Gerardo Sandoval is one of several Americans feeling uneasy during what is supposed to be a relaxing vacation.
"If I had known what I know -- yes, that there was a bombing just last week in Ankara, and I think there was one here also very recently -- I would have seriously thought about cancelling the trip."
Three Israelis were among those killed in Turkey's most recent bombing at an Istanbul shopping centre.
Local media have since reported the attacker specifically targeted an Israeli tourist group.
Now, Israel is warning its citizens living in or visiting Turkey to leave immediately, another potentially devastating blow to a country that relies heavily on tourism.
The Turkish government says the number of foreign visitors dropped by 10 per cent in February compared to the same time last year.
But economist Ozlem Bayraktar Goksen says a drop in Russian tourists, following Turkey's downing of a Russian warplane last year, has also contributed.
"It's not a surprise at all. Since last year's November, especially with heightening tension with Russia, the tourism sector has been in a struggle. And the number of tourist arrivals is declining, and, in the meantime, the revenues are declining as well."
Meanwhile, in Australia, the Department of Foreign Affairs and Trade is still advising Australians travelling to Turkey simply to exercise a high degree of caution.
