Iranian intelligence officers said Monday they thwarted one of the largest terrorist plots ever organized against the country, with plans to bomb the capital of Tehran and other locations, according to Iranian media outlets.

A statement from the Iranian intelligence ministry, cited by Iranian media, said that attacks were planned by Sunni extremists, but provided little other detail.

The semi-official Iranian Fars news agency quoted Ali Shamkhani, Supreme National Council secretary, as saying that bombings were slated to take place during the holy month of Ramadan.

“The Iranian authorities have apprehended several people suspected of trying to launch bomb attacks in Tehran,” Shamkani said, according to Fars.