The U.S. consulate general in Istanbul canceled public servicesWednesday, citing a possible security threat to the compound. While other consular posts in Turkey will run normally, the warning asked Americans to “maintain a high level of vigilance, be aware of local events, and take the appropriate steps to bolster your personal security.”

The closure comes just four days after the U.S. embassy in Turkey’s capital Ankara warned citizens to avoid diplomatic missions in Istanbul, Ankara, Adana and Izmir.
The announcement did not provide further information about the nature of the threat.