The U.N. nuclear agency chief said on Thursday a hacking incident involving one of its servers was “deeply regrettable” but suggested that no sensitive information related to Iran’s atomic activities had been stolen.

Yukiya Amano said the hacking – first reported by the International Atomic Energy Agency on Tuesday – had happened several months ago and that the server concerned had been closed down.

The hackers – a group using an Iranian-sounding name – on Sunday posted email addresses of experts who have been working with the United Nations on a website, and urged the IAEA to investigate Israel’s nuclear work.

“We don’t know everything (about the incident) but we are confident that safeguards information has not been stolen,” Amano told a news conference.

“Safeguards” means activities carried out by IAEA inspectors in investigating countries’ nuclear activities, including Iran’s, to make sure that no atomic material is diverted for weapons purposes.

(Reuters)