Iranian officials say four people have been arrested for trying to sabotage a nuclear plant.
The head of Iran's Atomic Energy Organization, Ali Akbar Salehi, told Iranian media that officials had monitored the suspects for some time, arresting them before they could do any damage to the nuclear site. The suspects are being interrogated.
Salehi did not reveal the plant the suspects had targeted. It was not immediately clear how long the suspects have been detained.
Israel sees Iran Iran's atomic work as a military threat and has said it will attack Iran's nuclear sites if it does not end its program.
Iran has long insisted its nuclear program is peaceful. The U.S. and some of its allies disagree, and have helped impose several rounds of sanctions that have battered Iran's economy.