The UN nuclear agency has confirmed that one of its servers has been hacked. A previously unknown group posted contact details of more than 100 experts working with the IAEA, calling on them to act against Israel’s alleged nuclear activities.

The group, called "Parastoo" – Farsi for the swallow bird and a common Iranian girl's name – published the names along with a statement "Parastoo Hacks IAEA" on November 25.

"Israel owns a practical nuclear arsenal, tied to a growing military body and it is not a member of internationally respected nuclear, biochemical and chemical agreements," the group said demanding the experts sign a petition calling for an “open IAEA investigation” into activities at Israel’s Negev Nuclear Research Center located near the city of Dimona.

It is commonly believed that Israel possesses nuclear weapons, though it has never confirmed, nor denied the fact. Tel Aviv however takes a hawkish stance against Iran, claiming that it is seeking to create weapons of mass destruction and describes the Islamic Republic as the greatest threat to the Middle East.

Tehran has strongly denied any allegations, insisting that its nuclear program is peaceful.

IAEA spokeswoman Gill Tudor said the agency "deeply regrets this publication of information stolen from an old server." She added that the server had been shut down some time ago and agency experts had been working to eliminate any "possible vulnerability" in it even before it was hacked.

The IAEA was doing "everything possible to help ensure that no further information is vulnerable," she said in an email, AP reports.

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