The attack hit the Shah Cheragh shrine in the southern city of Shiraz, with at least two children killed.
At least 15 people have been killed and 40 others injured in an attack on a Shiite religious shrine in the southern Iranian city of Shiraz, according to the country’s state media, IRNA.
The attack, which took place at the Shah Cheragh shrine in the early evening, was carried out by three armed men who entered the shrine, the report said.
Two of the attackers have been captured, and one is still on the run.
It is not clear who was behind the attack, but IRNA said the attackers acted as “takfiri terrorists”, referring to groups such as ISIL (ISIS).
Nour News, an Iranian state-affiliated media outlet, reported that the attackers were not Iranian nationals.
The Fars news agency said a woman and two children were among the dead.
“We were getting ready for prayers and then we heard the shot, we tried to escape from the other side and then I realized I was bleeding,” a witness and survivor of the attack told Al Jazeera.
“I couldn’t see who was shooting… It started from the street and then they came towards the shrine and shot whoever they saw. I saw some wounded and dead, but I didn’t see the attackers,” he said.
Fouad Izadi, a professor at Tehran University’s Faculty of World Studies, said the aim of the shooting was to “attack the faithful”.
“This is a trademark of ISIS: they attack mosques, they attack shrines,” Izadi said. “Whoever is behind this attack aims to secure the safety of the Iranian people.”
Al Jazeera’s Dorsa Jabbari, reporting from Tehran, said the shrine was an important site for religious pilgrims.
Shiraz is a popular pilgrimage and tourism destination, and the last such attack in the city was in April 2008, when a bomb planted in a mosque killed 14 people.
“This is a very rare incident that takes place at a very important time in Iran, when security is on high alert given the amount of protests that have taken place across the country,” Jabbari said.
Iran’s President Ebrahim Raisi vowed that the attack would not go unanswered, according to the semi-official Tasnim news agency.
“Experience shows that the enemies of Iran, after failing to create a split in the united ranks of the nation, take revenge through violence and terror. This evil will definitely not go unanswered, and security and law enforcement agencies will teach a lesson to those who masterminded the attack,” Raisi said.
Iran in June hanged a Sunni man who was sentenced to death for killing two Shiite clerics and wounding another in early April, the judiciary said at the time.
A 21-year-old man of Uzbek origin carried out the April 5 stabbing attack at the Imam Reza Shrine, which honors one of Shia Islam’s most revered figures.
The killings occurred during the Muslim holy month of Ramadan, when large crowds of worshipers had gathered at the shrine in Iran’s second-largest city, Mashhad.
Wednesday’s attack comes as Iran continues to face protests since the September death of Mahsa Amini, a 22-year-old who died after being arrested by the country’s morality police for wearing an “inappropriate hijab.”
Wednesday marked 40 days since Amini’s death, and thousands of people gathered in Amini’s hometown in northwestern Iran.