Reuters
Turkish flags are seen on the facade of the restored Great Synagogue before a re-opening ceremony in Edirne, western Turkey March 26, 2015. A five-year, $2.5 million government project has restored the Great Synagogue in the border city of Edirne, the first temple to open in Turkey in two generations.
An intelligence source told Sky News that the terror group was targetting kindergartens, schools and youth centres as well as Istanbul's synagogue in Beyoglu, which has a school attached to it.
"This is a more than credible threat. This is an active plot," the source told Sky News.
The information relative to those plots comes from ISIS members who were arrested in southern Turkey last 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," an intelligence source told Sky News.
In recent months, Turkey has been hit by a series of attacks orchestrated by ISIS - also known as the Islamic State, ISIL and Daesh - and Kurdish militants.
Though intelligence sources know the attack is planned soon, they are unsure of when it's expected to happen. "We don't know when it's scheduled for. It could be in the next 24 hours or next few days," the source said.
The last attack on March 19, killed four people, including at least two Israelis, and wounded 36. That one brought the death toll from attacks on Turkey in 2016 to more than 80.
Turkey is now hosting over 3 million refugees, many of whom have come into the country without undergoing any security checks. Many of the terrorists who are behind the attacks on Paris and Brussels came back from Syria with the thousands of refugees passing through Turkey.
Following the attacks in Brussels last week that killed 30 people and wounded over 200, ISIS has released a video vowing more attacks in Europe and also launched an online poll asking their supporters what country they should attack next (the