A gunman killed at least 15 people and injured dozens more after opening fire on worshipers at a pilgrimage site in Iran’s city of Shiraz on 26 October.

According to reports by the state news agency IRNA, the shooting took place at the Shah Cheragh shrine.

Initial reports claimed the attack was carried out by three gunmen, and that security forces managed to arrest two, while the third was still on the loose.

However, Amaq News Agency, a news outlet linked to ISIS, announced the organization’s responsibility for the attack on the shrine, specifying that the attack was carried out by just one member.

Shortly after the initial news broke, CCTV footage was released, showing the moment the attacker entered the shrine and opened fire.

🔴🇮🇷🎥 #IRAN: Here is the CCTV footage of today's US-Saudi backed takfiri terrorist attack at the Holy Shrine of #Shahcheragh in Shiraz, that killed dozen of innocent pilgrims including women and children. #شيراز#ایران#شاهچراغ https://t.co/iJwZMBxqnC pic.twitter.com/zIKuf1jezt

— Haidar Akarar  (@HaidarAkarar) October 26, 2022

Earlier this year in August, Iran arrested 10 militants linked to ISIS. According to Iran’s Ministry of Intelligence, the suspects planned to carry out terrorist attacks on religious gatherings.

These arrest operations were carried out in two different locations in southern and western Iran and lasted for three days. Reportedly, two intelligence officers were injured during a gunfight with the militants.

The recent and often violent protests have added to the security concerns of Iran, when armed groups launched an attack on a police station in Zahedan, before opening fire outside a mosque. The attack resulted in the deaths of two commanders of the Islamic Revolutionary Guard Corps (IRGC), which vowed a “decisive response.”

More than 300 people have been charged in Tehran in connection with street protests that started after the death of Mahsa Amini. Four of them could face the death penalty, authorities announced on 24 October.

According to Tehran prosecutor Ali Salehi, quoted by the Mizan Online judicial authority website, 315 people are charged with “gathering and conspiracy against the security of the country,” as well as “propaganda” and “disturbing public order.”

Iran has been rocked by popular unrest for the past several weeks, following the death of 22-year-old Mahsa Amini, who fell into a coma hours after being detained by the Moral Security Police on 13 September. She passed away in a hospital three days later due to multiple organ failure caused by cerebral hypoxia.