At least 10 people have been killed, including members of Iran’s elite Revolutionary Guards, and at least 21 people wounded after militants opened fire on a military parade in the southwestern city of Ahvaz. Shots were fired from behind a stand during the parade, which took place to mark the start of the 1980-88 Iran-Iraq war. A journalist was also among those killed in the attack. Iran’s official news agency, the IRNA, put the number of those injured at 21.

Two of the attackers were killed by security forces and two arrested. Student news agency ISNA reported that Brigadier General Ramezan Sharif, a spokesman for the guards, had said the attackers were members of Alahvaziyeh Group, a pan-Arab separatist group seeking independence from Iran and supported by Saudi Arabia. Iran and Saudi Arabia have been locked in a power struggle in the region for years. Tehran and Riyadh, self-proclaimed custodians of Shia and Sunnis in the Islamic world, are involved in proxy wars in the region, including in Syria and Yemen. Mohammad Javad Zarif, Iran’s foreign minister, also accused the US and some unnamed regional countries of being involved in the attack.

“Iran holds regional terror sponsors and their US masters accountable for such attacks. Iran will respond swiftly and decisively in defense of Iranian lives,” he posted in a tweet. Brig Gen Sharif said that the attack was launched to “overshadow the greatness of the armed forces parades [across the country]”.

State television aired footage of paramedics helping people in the aftermath of the attack while sirens wailed. Hassan Rouhani, Iran’s president, was forced to leave a military parade in Tehran early following the attack in Ahvaz. The incident is the second in recent years following simultaneous attacks by gunmen and suicide bombers on the parliament building in Tehran and the nearby shrine of Ayatollah Ruhollah Khomeini, the Islamic Republic’s founder in June 2017.