Israel expects terrorist attacks on its citizens in the Turkish metropolis of Istanbul by Iranian agents this weekend.
There are concrete indications of attacks, Israeli media reported on Friday evening, citing high-ranking officials.
Israeli tourists should therefore leave Istanbul as soon as possible.
Anyone who cannot walk should stay in their hotel room, lock the doors and not open them to strangers.
Israel issued a travel warning for Turkey at the end of May due to the threat of attacks.
After the shooting of a member of the Revolutionary Guards (IRGC) in Tehran, Iran's President Ebrahim Raisi announced retaliation.
Iran blames Israel and the US.
Tehran considers Israel its arch-enemy.
Israeli media reported that Israeli and Turkish security forces searched Istanbul's streets for attackers on Friday.
Iranians and Turkish recruits were looking for Israelis at all costs.
The Haaretz newspaper reported that several cells were working on attacks at the same time.
It could therefore be difficult for security forces to thwart all attacks.
According to Israel, it has recently prevented several attack plans from Tehran, including an assassination attempt on a US general in Germany.
According to information from several media outlets, around 2,000 Israelis are currently in Turkey.