UPDATE 1300 GMT: The Islamic State has claimed responsibility for the gun attack in Ahvaz.

UPDATE 1030 GMT: The death toll in today’s attack in Ahvaz has been raised to 24.

State media say the toll is likely to rise further, with many of the wounded in critical or serious condition.

At least 11 people have been killed and 20 people wounded in an attack on a military parade in southwest Iran.

Gunmen fired in Ahvaz on a military parade which was marking the start of the Iran-Iraq War of 1980-1988. The attackers targeted a stand where Iranian officials were gathered.

Iranian outlets said at least eight members of the elite Revolutionary Guards were among those killed. Two attackers were reportedly slain. Some accounts say two more were detained, but others say the men fled.

The capital of Khuzestan Province, Ahvaz has a large Arab population, and there have been periodic protests and occasional unrest over many years about the regime’s economic and social policies. Separatists have carried out attacks on oil pipelines.

Iranian Foreign Minister Mohammad Javad Zarif blamed regional countries and their “US masters” for today’s attack.

Last year, an attack by Islamic State fighters in Tehran killed 18 people at the Parliament building and at the mausoleum of Ayatollah Khomeini, the founder of the Islamic Republic.

Images from today’s attack: