On Saturday night, the Turkish police issued a warning that the Islamic State (ISIS) is planning on attacking synagogues and churches on Sunday, which is the holiday of Easter.

The police issued a nation-wide alert, saying that ISIS operatives may have scouted out non-Muslim places of worship, embassies, consulates, or any other religious buildings, targeting them for attack.

The warning, issued in the state-run Anatolia news agency, said the police were searching for three Islamic terrorists.

The warning comes one week after three Israelis were killed and eleven others injured in an ISIS bomb attack that may have targeted the Israelis for their nationality.

ISIS has been responsible for four bombings in Turkey in the last eight months, including one at a peace rally in Ankara in October that killed 103 people.

American nationals registered with the U.S. Embassy in Turkey’s capital of Ankara were sent alerts via email and text messages saying, “U.S. citizens are reminded to maintain situational awareness and the ability to communicate in an emergency. Keep a low profile, stay away from crowds and demonstrations and avoid becoming time and place predictable.”