“No increase in radiation levels was reported,” it wrote on X.
It said nuclear power plant sites and nearby areas “must never be attacked” and called for “maximum military restraint” to avoid a nuclear accident.
On 27 March US President Donald Trump announced he was pausing attacks on energy plants for 10 days for Iran to “make a deal”, and on Saturday he reiterated his threat on Truth Social that “all Hell will reign down on them” if they failed to do this, or to reopen the Strait of Hormuz, within 48 hours.
Meanwhile, Iran has continued to fire missiles at the Gulf States, Iraq and Israel, with falling debris from intercepted missiles causing damage.
And both Iranian and US forces are continuing to search for a missing American crew member after an F-15 fighter jet was shot down on Friday.
A pilot who was on board has been rescued, according to US media.