Tehran's decision to move the facility comes as diplomatic efforts to restore Iran’s tattered nuclear deal appear stalled.
Iran has confirmed it relocated a centrifuge facility to its underground Natanz nuclear site, days after the UN atomic watchdog said it installed surveillance cameras to monitor the new workshop at Tehran's request.
The state news agency IRNA quoted the spokesman for Iran’s atomic energy organisation, Behrouz Kamalvandi, on Saturday as saying authorities had moved the operation to a safer place.
“Unfortunately because of a terrorist operation that took place against Karaj, we were obliged to intensify security measures under which we moved an important part of the machines and transferred the rest to Natanz and Isfahan,” said Kamalvandi.
Isfahan is the location of another Iranian nuclear facility.
Iran’s centrifuge facility in Karaj found itself targeted in what Iran described as a sabotage attack in June.
Natanz itself has twice been targeted in sabotage attacks amid uncertainty over the nuclear deal, assaults that Iran has blamed on Israel.
Nuclear deal talks stalled
On Thursday, The Vienna-based International Atomic Energy Agency said it installed cameras and removed seals from machines at the new workshop in Natanz two days earlier.
Those machines will be used to make centrifuge rotor tubes and bellows, crucial parts for the devices that spin at very high speeds to enrich uranium gas.
Talks between Iran and world powers in Vienna to revive the 2015 nuclear deal have stalled. There is concern that Iran could be closer to being able to construct an atomic weapon if it chose to pursue one.
The nuclear deal collapsed four years ago when former President Donald Trump withdrew the United States and imposed crushing sanctions on Iran.
Kamalvandi reiterated Iran’s stance that Tehran will not provide data from the cameras to the UN nuclear agency if a deal is not concluded.