A suicide vehicle bomber attacked a police headquarters in the southeastern Iranian port city of Chabahar on Thursday, killing at least three people and wounding several others, state TV reported.
TV also reported shooting in the area, which is located in the mainly Sunni province of Sistan-Baluchestan that has always been plagued by unrest from both drug smuggling gangs and separatist militants.
"The terrorists tried to enter Chabahar police headquarters but they were prevented by the guards and they detonated the vehicle bomb", Marashi said without elaborating on how many assailants took part.
"Three people were killed and some others were injured", Chabahar's acting governor Rahmdel Bameri told state television.
The report went on to say that shooting could also be heard in the city.
"We express our condolences to the government and the people of Iran and the families of the victims of this attack", the Ministry of External Affairs said.
Jaish al-Adl (Army of Justice), a Sunni militant group that has carried out several attacks on Iranian security forces, mainly in Sistan-Baluchestan, claimed responsibility for an attack that killed 10 border guards near Pakistan in 2017.
State TV also aired footage of smoke rising over the city.
The attack comes as Iran's economy reels in the wake of the United States re-imposing sanctions lifted by Tehran's nuclear deal with world powers.
The attack was claimed by a Sunni separatist group called Jundullah (Soldiers of God).
It said India condemned the "despicable terror" attack.
Chabahar is a key port city on the Gulf of Oman about 100 kilometers west of Iran's border with Pakistan.