Turkish security officers on alert. (Depo Photos via AP)

Israel’s Counter-Terrorism Bureau is warning of a possibly imminent ISIS attack in Turkey and is urging all Israeli citizens to leave.

Israel’s National Security Council Counter-Terrorism Bureau (NSCCTB) has issued an updated travel advisory for Turkey on Monday, warning its citizens to leave the country as soon as possible and avoid traveling there.

The NSCCTB upgraded its warning from “a basic concrete threat” to “a high concrete threat,” the second-highest warning level. This warning was issued after the NSCCTB issued a warning last week in wake of an Islamic State (ISIS) bombing in Istanbul last Saturday that killed three Israeli tourists and an Iranian national, and wounded several others.

In the warning, the NSCCTB writes that the Istanbul attack ”underscores the threat by Daesh [Arabic acronym for ISIS] against tourist targets throughout Turkey and proves high capabilities of carrying out further attacks. Terrorist infrastructures in Turkey continue to advance additional attacks against tourist targets – including Israeli tourists – throughout the country.”

Therefore, the NSCCTB “reiterate our recommendation to the public to avoid visiting the country and – for Israelis currently in Turkey – to leave as soon as possible.”

Over the weekend, Turkey issued a warning of pending ISIS attacks against Christian and Jewish targets in its country. The warning said the Islamic terror group was seeking to target Christians on Easter, and Jewish synagogues.

Turkey has been struck by six suicide bombings in the past few months, resulting in over 200 deaths.