A sound bomb exploded early Wednesday in southeast Iran injuring four police officers, the official IRNA news agency reported.
The incident took place in the city of Zahedan, the capital of the Sunni-populated southeastern province of Sistan-Baluchestan.
A sound bomb exploded near a police vehicle causing damage to the vehicle and injuring four police officers, the Islamic Revolutionary Guard Corps (IRGC) said in a statement, according to IRNA.
No group has so far claimed responsibility for the attack.
For years, the Iranian military has clashed with militant groups in the region who say they are seeking improved rights and living conditions for mostly Sunni ethnic minority Baluchis in southeast Iran.
In June, a roadside bomb hit two IRGC vehicles in Sistan-Baluchestan injuring an IRGC commander, state media reported.
Iran said the Sunni militant group Jaish al-Adl (Army of Justice) was behind the attack. The group, formed in 2012, has been behind several attacks against Iranian forces in recent years.
In 2019, Jaish al-Adl claimed responsibility for a suicide car bomb attack against a bus carrying members of the IRGC which killed 27 troops.