Israel's National Security Council on Monday raised its travel warning for Turkey for the second time in eight days.
The authority raised the travel warning to level two, meaning a "high, concrete threat," after raising it on March 20 to level three, meaning a "basic, concrete threat."
Before that there had been a general, non-concrete level-four warning.
The updates followed a suicide bombing in Istanbul on March 19, in which three Israeli tourists and an Iranian citizen were killed and dozens of people were injured.
Citing "concern for additional attacks," the Israeli body on Monday called on Israeli citizens not to visit Turkey at this time and on those already there to "leave at the earliest opportunity."
It said it had reason to believe that the extremist militia organization Islamic State was planning more attacks against tourists, especially Israelis.