Israel reportedly struck one of Iran’s secret nuclear research facilities in a retaliatory operation in late October, according to a Friday Axios report citing former and current US and Israeli officials.

In particular, according to the publication, the attack caused significant damage to the Parchin military complex, about 20 kilometers southeast of Tehran.

The strike dealt a serious blow to Iran’s nuclear development efforts, the officials cited by the report claimed.

A former Israeli official said the Israeli airstrike destroyed sophisticated equipment used to design the plastic explosives that surround the uranium in a nuclear device and are necessary to detonate it.

The facility was reportedly part of Iran’s Amad nuclear weapons program until 2003. It was then used to test explosives needed to detonate a nuclear device, the report cited the Institute for Science and International Security as saying.

The International Atomic Energy Agency (IAEA) board will meet next week and is expected to pass a resolution of censure against Iran for its lack of cooperation with the UN nuclear watchdog. Iran has said it may respond by curtailing its cooperation with the IAEA.

IAEA Director General Rafael Grossi visited Iran on Wednesday and Thursday ahead of the board meeting.

Araghtsi told Grossi that Iran is willing to negotiate with France, Germany and the United Kingdom “on its peaceful nuclear program … but it is not ready to negotiate under pressure and intimidation.”