The Department of State ordered Saturday the recall of all family members of employees working at the U.S. Consulate General in Istanbul, citing serious security concerns in the country.

The order coincided with a new travel warning for U.S. citizens currently in or planning on traveling to Turkey. The State Department announced it "made this decision based on security information indicating extremist groups are continuing aggressive efforts to attack U.S. citizens in areas of Istanbul where they reside or frequent."

Turkey has been the victim of numerous terrorist attacks from both the Islamic State group, an extremist fundamentalist group active in Iraq and Syria, and the Kurdistan Workers Party, a militant pro-Kurdish independence party. Most recently, an explosion on Tuesday rocked the southern Mediterranean resort city of Antalya, wounding several people.

In August, two missiles struck another resort town in the same province. While these attacks did not cause massive casualties, they did occur in popular travel destinations. A suicide bombing that same August killed over 50 at a wedding party in Gaziantep.

The unrest has had a negative effect on Turkey's tourism. Between May 2015 and May 2016, arrivals fell 34.7 percent to 2.48 million, the lowest drop in over two decades. While security fears and a failed coup attempt in June certainly kept travelers away, another major contributor to the decline was Russia's decision to ban its citizens from traveling to Turkey after Turkish pilots shot down a Russian jet over Syria in November they claimed had violated the country's airspace.

Despite the lifting of the ban in June, tourism did not improve, with tourism from the U.S. alone plummeting 60 percent in 2016. A number of high-profile tour businesses such as the U.K.-based Mark Warner Holidays have pulled out of the country. Meanwhile, Turkey's domestic tour company Anatolian Sky flopped altogether.

Like the U.S., other countries have advised their citizens against travel to Turkey. The U.K.'s Foreign and Commonwealth Office said that "there is a high threat from terrorism" and instructs its citizens to be "vigilant at this time."

Other governments such as those of Australia, Canada, Hong Kong and Ireland have travel advisories in place for Turkey or certain parts of the country. While no country has officially banned travel to Turkey—no recent attacks have officially been determined to have targeted tourists—many countries have issued precautions, especially concerning travel to Turkey's southeastern border with Syria.