For the first time in Israel's 63-year old battle against terror, its external security agency Mossad Thursday night, April 21, issued a strong warning to travelling Israelis to beware of a major terrorist attack which Hizballah had already set in motion at some undisclosed location. The only information attached to the warning was that Hizballah had consigned a high-profile team for an operation to avenge the slaying of its top commander Imad Mughniyeh three years ago for which it blames Israel.

The warning was not issued as an official notice but leaked through mainstream media and marked red alert. As one source put it, "The wedding has begun." debkafile's counter-terror sources interpreted this extraordinary communication to the public as meaning that Hizballah's plot is too advanced for Israel's counter-terror agencies to preempt at source and a hectic race is afoot for them to beat Hizballah to its target or at least limit the damage.
No Israeli intelligence would disclose the location or country where the attack was to take place, only that the timeline was "immediate." Many thousands of Israelis are spending the long Passover festival vacation outside the country.
The only information released was as unusual as the rest of the notice: it was the identities of the Hizballah masterminds who set up, prepared and are running the operation.

This is the first time any Western or Middle East intelligence agency has ever released the names of terrorist masterminds before an attack. It normally takes months or even years for their identities to be discovered and even longer for their disclosure.
The Mossad may have put their names in the public domain in the hope of somehow stalling the Hizballah operation in the nick of time:
The five top Hizballah terrorist operatives named are:

Talal Hamiyah, head of Hizballah's External Security Organization – ESO. Deputy of the late Moughniyeh for many years, Hamiyah stepped into the slain terror-master's shoes as commander of overseas operations. Hizballah's Secretary General Hassan Nasrallah has entrusted him with avenging the death of his late boss.
Ahmed Al-Fayd, Hamiyah's operations officer and right hand.
Najem a-Din, Hizballah's bomb expert.
Naim Haris. In the guise of a Lebanese businessman, he is responsible for recruiting collaborators in different countries for Hizballah's overseas hits.
Mehmet Taharawrlu, a Turkish national who recruites local talent to assist in Hizballah attacks in Turkey.