Details of the attack and the number of casualties remain unclear
Chabahar attack: Suicide bomb kills two in southeast Iranian city
A suicide car bomb attack on a police station killed at least two people in the southeast Iranian city of Chabahar on Thursday, according to a revised official toll.
"This terrorist act led to the martyrdom of two members of the police force," the province's deputy governor in charge of security, Mohammad Hadi Marashi, told state television.
Chabahar city governor Rahmdel Bameri said earlier that four people were killed and many more wounded when the bomber blew up a car, but later revised the death toll to two.
Fars News, a semi-official Iranian news agency, said the "suicide incident" took place near a police station. A security official told the agency that security and emergency services had been deployed to the area.
"The explosion was very strong and broke the glass of many buildings close by," Mr Bameri told state television.
Many nearby shop owners and civilian passers-by, including women and children, were severely wounded, he added.
Another official told state television: "This morning a bomb inside a car exploded near a police station in Chabahar and four people were injured," the official said.
An official told TV that "the terrorist who carried out the attack was killed". He did not elaborate.
State authorities did not identify who was behind the attack. No militant group immediately claimed responsibility for the attack.
State TV also aired footage of smoke rising over the city.
Chabahar is a deep sea port city located in the Sistan and Baluchestan Province on the Gulf of Oman and Iran's southernmost population centre, hosting around 100,000 people. It is situated near the border with Pakistan and is an economic free zone for the country.
If confirmed, the attack comes less than three months after armed gunmen launched an assault on an Iranian military parade in the southwestern city of Ahvaz. The September 22 attack, claimed by the Ahvaz National Resistance, left 25 people dead.
Iran accused the US and Gulf states of involvement and vowed revenge.
Suicide bombings are rare in Iran, but Sunni militant groups have carried out several attacks on Iranian security forces in the Sistan-Baluchestan province in recent years.
Last year, in the first deadly assault claimed by ISIS in Tehran, 18 people were killed at the parliament and mausoleum of Ayatollah Ruhollah Khomeini, founder of the Islamic Republic.
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.
In 2010, two suicide bombers killed at least 28 people, including some of the elite Revolutionary Guards, at a Shi'ite mosque in southeast Iran, an attack Iranian leaders said was backed by the United States.
The attack was claimed by a Sunni separatist group called Jundullah (Soldiers of God).
Tehran accuses its Sunni-led regional rival Saudi Arabia and the United States of funding most of these groups, a charge that Riyadh and Washington deny.
Iran also says that militant groups are sheltering across the border in Pakistan and has threatened to attack their bases if Islamabad does not confront them.
The attack comes as Iran's economy reels in the wake of the US reimposing sanctions lifted by Tehran's nuclear deal with world powers. While Iran still complies with the accord, President Donald Trump withdrew America over the deal in part due to Tehran's ballistic missile program, its "malign behavior" in the Middle East and its support of militant groups like Hezbollah.