TEHRAN - At least five Iranian police officers were killed Tuesday in an attack in the restive Sistan-Baluchistan province in the country's southeast, state TV reported.

Local media reported that a Sunni Muslim jihadist group, Jaish al-Adl, had claimed responsibility for the shooting, but a local official said criminal gangs were to blame.

"A number of armed miscreants in the region attacked a police patrol," Alireza Marhamati, deputy governor of Sistan-Baluchistan province told state TV.

"Five of our dear policemen were martyred and one person was injured there," he said.

Marhamati added that security forces were looking for the attackers, insisting they were not Jaish al-Adl members.

"It is not their job," he said, arguing the jihadists had claimed the attack "to make themselves bigger".

According to Iranian news agency Tasnim, two police vehicles came under fire along a road in Sistan-Baluchistan, long plagued by unrest involving drug-smuggling gangs, rebels from the Baluchi minority and Sunni extremists.

Last week militants from Jaish al-Adl -- branded a "terrorist" organisation by Iran and the United States -- killed 16 security personnel in one of their deadliest attacks in years, also in Sistan-Baluchistan near the Pakistani border.

The fatalities included law enforcement officials, members of the Islamic Revolutionary Guard Corps and paramilitary Basij forces, according to a Tasnim report which said US weapons and technology were seized from the "terrorists".

The latest violence came amid heightened security concerns as the holy Muslim month of Ramadan draws to a close this week.

State media said Saturday that Iranian police had arrested three suspected Islamic State (IS) group members over plans to carry out attacks at the end of Ramadan.

Official news agency IRNA reported that the arrests had been made in the northwestern city of Karaj but did not specify when or elaborate on the suspects' identities.

In January IS claimed responsibility for twin bombings that killed more than 90 people in the southern city of Kerman, at a commemoration for top Revolutionary Guards general Qasem Soleimani who was killed in a US strike in 2020.