Prime Minister Benjamin Netanyahu cut short a trip abroad after the U.S. killing of Iranian commander Qassem Soleimani drew promises of revenge from Iran.
Israel, America's closest ally in the Middle East and Iran's top regional foe, has not publicly responded to the death of Quds Force chief Soleimani and Iraqi militia commander Abu Mahdi al-Muhandis in the U.S. air strike in Baghdad.
But Netanyahu's office confirmed that he would return home early from Greece. Israel's Army Radio said the military was on heightened alert and Defence Minister Naftali Bennett met military and intelligence chiefs for a "situational assessment".
Members of Netanyahu's security cabinet have been asked not to comment on the high-profile killings, which Israeli media interpreted as a bid to stave off retaliation from Iran's proxies and allies in the region.