VIENNA (AP) — The International Atomic Energy Agency has acknowledged that one of its servers has been hacked.

The UN nuclear watchdog commented Tuesday after a previously unknown group critical of Israel’s undeclared nuclear weapons program posted contact information for more than 100 experts working for the IAEA.

A group called “Parastoo” — Farsi for a swallow bird and a common Iranian girl’s name — claimed responsibility for posting the names on its website two days ago.

Israel is commonly acknowledged to possess nuclear weapons — something it neither confirms nor denies. It says Iran is secretly working on nuclear arms — something Tehran denies — and describes the Islamic republic as the greatest threat to the Mideast.

Iran and Arab countries, however, say the Jewish state’s nuclear capacities pose the greatest menace.

Copyright 2012 The Associated Press.