VIENNA: Tehran on Friday accused Yukiya Amano, the head of the UN atomic watchdog, of putting Iran's nuclear scientists at risk of assassination by "terrorists" and US and Israeli agents.

"The international community is ... witnessing (the) ugly phenomenon of assassination of Iranian nuclear scientists and experts by terrorist groups," Iran's envoy to the International Atomic Energy Agency (IAEA) told Amano by letter.

"The release of the names of Iranian nuclear scientists.. (by the IAEA) has made them targets for assassination by terrorist groups as well Israeli regime and United States of America intelligence services," Ali Soltanieh said.

The November 16 letter, an English version of which was made available by the Iranian diplomatic mission in Vienna, said the names were leaked in the annex to the IAEA's recent damning report on Iran's nuclear programme.

Soltanieh said releasing the names, which he said have also appeared in US and European Union sanctions lists, was contrary to IAEA rules and that he reserved the right to take "appropriate legal measures."

Amano is "accountable for any security threat against the lives of my fellow citizens referred to by you and their families as well as sabotage against locations indicated on your report based on baseless allegations."

Last week's IAEA report came the closest yet to accusing Iran of seeking to develop nuclear weapons. The IAEA's 35-nation board was expected to approve later Friday a resolution expressing its "deep and increasing concern."