Gambrell tweeted, "an official from the state electric energy company said on a talk show that the Bushehr plant shutdown began on Saturday and would last for three to four days." 

There was no immediate word on why the Bushehr Nuclear Power Plant, located 10.5 miles southeast of the city of Bushehr, was shut down.

He added, "This is the first time Iran has reported an emergency shutdown of the plant. It went online in 2011 with help from Russia. Tehran previously warned sanctions barred it from getting parts for the plant."