According to Sky News, citing an “intelligence source,” terrorists from the Islamic State are plotting to attack a synagogue which also doubles as a school and community center in the Beyoglu neighborhood of Istanbul.

The source said the threat was imminent and could happen at any moment

“The most likely target of an attack is Istanbul’s synagogue in Beyoglu, which also has a community center and a school attached to it,” Sky reported.

The information was apparently obtained from six Islamic State operatives who were arrested in southern Turkey over past week

"In light of these circumstances, extraordinary security measures are being taken above and beyond the high alert level already in place by the Turkish police, as well as vigilance within the Jewish community," Sky News quoted an intelligence source as saying. "Undercover and other covert counterterror measures are being implemented around the clock. This is a more than credible threat. This is an active plot."

The intelligence source went on to say of the potential attack, "We don't know when it's scheduled for. It could be in the next 24 hours or next few days."

On Sunday, Israel urged its citizens visiting Turkey to leave "as soon as possible" in an upgraded travel advisory on Monday predicting possible follow-up attacks to the March 19 suicide bombing in Istanbul blamed on Islamic State.

Three Israeli tourists and an Iranian were killed in the Istanbul attack, which prompted the Counterterrorism Bureau in Prime Minister Benjamin Netanyahu's office to issue a generalized "Level 3" warning against travel to Turkey.