Gunmen attack Iran military parade, killing at least 24

Gunmen attacked an annual Iranian military parade Saturday in the country's oil-rich southwest, killing at least 24 people and wounding 53 others, local media reported.

No group immediately claimed responsibility for the assault in Ahvaz, which saw gunfire spray into a crowd of marching Guardsmen, bystanders and government officials watching from a nearby riser.

However, Iran faced a bloody assault last year from the Islamic State group and Arab separatists in the region have attacked oil pipelines there in the past.

Iran's Foreign Minister Mohammad Javad Zarif immediately blamed the attack on regional countries and their "US masters," further raising regional tensions as Tehran's nuclear deal with world powers is in jeopardy after President Donald Trump withdrew America from the accord.

"Iran will respond swiftly and decisively in defense of Iranian lives," he wrote on Twitter.

State television aired footage of the aftermath of the assault on Ahvaz's Quds, or Jerusalem, Boulevard, which like many other places around the country saw an annual parade marking the start of Iran's long 1980s war with Iraq.

The images included paramedics trying to help one person in military fatigues as other armed security personnel shouted at each other.

The semi-official ISNA news agency published photographs of the attack's aftermath, with bloodied troops in dress uniforms helping each other walk away.

A local news agency in Khuzestan province, of which Ahvaz is the capital, aired grainy mobile phone footage showing parade goers fleeing as soldiers lay flat on the ground. Gunfire rang out in the background.

"Security forces have restored security in the area but the parade has totally been disrupted," a reporter on the scene for Iranian state television said by phone in a live broadcast.

"People have been killed but we have no figures yet."