Supreme leader Ayatollah Ali Khamenei -- who has the final say in all matters of the state in Iran -- has vowed that Nasrallah's death "will not be in vain".

Israeli Prime Minister Benjamin Netanyahu told Iranians on Monday that there was nowhere in the Middle East beyond Israel's reach, three days after Israel's military killed the leader of Iranian-backed Lebanese militant group Hezbollah.

Israeli special forces have launched deadly raids inside Lebanon ahead of a feared ground invasion to try and wipe out Hezbollah's rocket and missile teams.