The authorities did not identify who was behind the attack.
At least three people have been killed following a suicide auto bombing attack near a police post in Iran's southern port city of Chabahar, state television Press TV reported, quoting security and local officials.
"Terrorists attacked the police post in Chabahar with an explosives-laden vehicle", he said.
The state news agency IRNA said some 24 people had been wounded.
"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.
There was no immediate claim of responsibility for the attack.
State TV also showed footage of smoke rising over the city.
The southeastern port city in Iran's Sistan and Balochestan province is located near the border with Pakistan.
Iran has stepped up security in border areas after gunmen in September opened fire on a military parade in Iran's southwestern city of Ahvaz, killing 25 people, nearly half of them members of Iran's elite Revolutionary Guards corps.
No militant group immediately claimed responsibility. Another coordinated June 7, 2017 IS group assault on parliament and the shrine of Ayatollah Ruhollah Khomeini, the leader of Iran's 1979 Islamic Revolution, killed at least 18 people and wounded more than 50.
While rare, Iran has been targeted in recent years by militant attacks.
Chabahar is a free trade zone and the site of an Indian-backed port complex being developed as part of a new transportation corridor for landlocked Afghanistan.