The assailants targeted Police Station 16, located south of the Sunni Musalla (prayer hall) of Zahedan.
Reports suggest that the attackers were wearing suicide vests and two of them have blown themselves up.
Shooting was heard in the area as some sources said the assailants tried to storm into the Police station.
Witnesses said the terrorists have scaled a watchtower of the Police station and were shooting at the cops from above.
The Police forces inside the station and the security forces outside the base have surrounded the assailants amid the heavy exchange of fire.
Located in the southeast of Iran, Sistan and Balouchestan borders Pakistan and Afghanistan and has a long coastline by the Sea of Oman.