United Nations atomic agency chief Rafael Grossi has been receiving 24/7 protection from a tactical security unit based out of Austria, amid what's been reported as specific threats on his life connected to Iran.

Tuesday reporting in The Wall Street Journal has revealed Grossi has received this protection for weeks. Austria’s Cobra special services unit is providing the security detail. It is part of the Austrian Federal Ministry of the Interior.

WSJ details that "The elite unit of Austria’s security services is protecting Grossi after the country’s intelligence agency received information of a threat to the International Atomic Energy Agency chief from a third party, according to a person involved in the case. The IAEA is based in Vienna."

Officials are citing a "specified Iranian threat" - but haven't disclosed precise details of the threat. But it was apparently enough to take drastic action, as "The tactical force is deployed to counter the gravest threats, such as terror plots and to secure top-ranking individuals, including the Austrian chancellor."

"In instances of concrete threats against dignitaries, the unit deploys officers armed with submachine guns and at least two bulletproof vehicles around the clock," according to WSJ.

Iranian leaders have blasted the IAEA connected with the 12-day June where, when Israel led a surprise attack, which was ended when the US military dropped huge bunker-buster bombs on three nuclear sites.

Tehran has accused the UN inspectors of essentially spying, and passing sensitive information on to the Israelis. Some Iranian state media reports have gone so far as to label Grossi an Israeli spy.

According to more in WSJ:

A person familiar with the matter said the Austrian authorities acted on intelligence outlining a specific threat to Grossi coming from Iran-linked individuals. A second person said they had been told that the threat was believed to come from Iran and was being taken seriously by authorities.

“We can confirm that Austria provided a Cobra unit but we cannot confirm where the specific threat came from,” said Fredrik Dahl, an IAEA spokesman.

Some veiled threats from top Iranian advisers have actually been articulated quite publicly...

Grossi, who is a veteran Argentine diplomat is said to be in the running to succeed António Guterres as United Nations secretary-general. Guterres term in the post will end next year.