At least 24 people, including civilians were killed and over 50 injured when gunmen disguised as soldiers opened fire on an elite military parade in the Iranian city of Ahvaz on Saturday.

The parade was part of nationwide celebrations in Iran to mark the 30th anniversary since the end of the eight-year war with Iraq that started in September 1980 and ended in August 1988.

“The terrorists disguised as Islamic Revolution Guards Corps (IRGC) and Basiji (volunteer) forces opened fire during the parade,” Governor of Khuzestan Gholam-Reza Shariati was quoted as saying by IRNA news agency.

Fars news agency said the attack started at 9 am and appeared to involve four gunmen. The attackers shot from a park near the parade and were wearing military uniforms.

“The terrorist team was annihilated, two of them were killed and other two were arrested. One of the detained terrorists was injured,” said Shariati.

Military personnel and a journalist were among those killed.

Iranian Foreign Minister Mohammad Javad Zarif blamed “a foreign regime” backed by the US for the attack. “Terrorists recruited, trained, armed and paid by a foreign regime have attacked Ahvaz,” he said in a tweet, adding: “Iran holds regional terror sponsors and their US masters accountable for such attacks.”

Earlier, Iranian President Hassan Rouhani used the occasion of the military parade to compare US President Donald Trump to the former Iraqi dictator Saddam Hussein, according to Press TV.

Speaking at a military rally in Tehran, he said Trump will fail in the “economic and psychological war” he’s launched against Iran, just as Hussein failed in his 8-year war against the Islamic Republic”.

“Iran will neither abandon its defensive weapons nor will reduce its defence capabilities,” Rouhani said.

“Rather it will increase its defence power day by day. The fact that they are angry at our missiles shows that these are the most influential weapons Iran has.”