The first blast occurred at 9:20 p.m. in front of the city's Grand Mosque, and the second explosion followed within minutes, IRNA said.

The news agency reported that at least 20 people were killed and 100 were wounded. Iran's state-run Arabic channel, Al-Alam, reported that at least 30 were killed and more than 50 wounded.

"It is not yet possible to announce the exact number of those killed and injured in the incident," a police official said, according to IRNA. Zahedan is the capital of Sistan-Baluchestan province, which borders Pakistan.

Iranian Deputy Interior Minister Ali Abdollahi labeled the incident a terrorist act, the semi-official Fars news agency said.

"Terrorist operations in Zahedan have left several dead and injured," Abdollahi said, according to Fars.