Supreme Leader Ayatollah Ali Khamenei has been taken to a secure location inside Iran amid heightened security, sources said, a day after Israel killed the head of Iran-backed Lebanese group Hezbollah in a strike on Beirut.

The move to safeguard Iran's top decision-maker is the latest show of nervousness by the Iranian authorities as Israel launched a series of devastating attacks on Hezbollah, Iran's best armed and most well-equipped ally in the region.

It was reported this month that Iran's elite Revolutionary Guards Corps, the ideological guardians of the Islamic Republic, had ordered all of members to stop using any type of communication devices after thousands of pagers and walkie-talkies Hezbollah used blew up.