Occupied Jerusalem: Israel has issued an advisory warning citizens abroad of likely kidnapping attempts after Hezbollah's chief vowed revenge for the killing of a senior commander.

Israeli military and embassies were on alert on Friday and Jewish institutions worldwide were advised to follow suit, the Haaretz newspaper reported.

"The danger of Hezbollah carrying out terror attacks against Israeli targets abroad is escalating," according to a statement from the Prime Minister's Office.

Hezbollah leader Hassan Nasrallah on Thursday threatened to attack Israeli targets for the death of Emad Mughnieh, who was killed in a car bombing in Syria on Tuesday.

"If you want this kind of open war, then let it be an open war of this kind," Nasrallah said. Israel has denied involvement in the killing.

Israeli soldiers have been ordered to be on guard for possible attacks on the borders with Lebanon and Palestinian territories.

The Counter-Terrorism Bureau also issued warnings against travelling in places abroad where there are high concentrations of Israelis, especially tourist attractions.

In the United States, the FBI has put terror squads on alert for threats against synagogues and other potential Jewish targets.