Thousands of people took part in protests Friday in Tehran and other Iranian cities to denounce a mass shooting at a key shrine that killed more than a dozen worshippers. The Sunni Muslim extremist Islamic State group claimed responsibility for Wednesday’s attack on the Shiite shrine of Shah Cherah in the southern city of Shiraz. Authorities said at least 15 people were killed and 19 others were wounded when a lone gunman stormed the holy site and fired at worshippers during evening prayers. State television broadcast live footage as crowds gathered after weekly Friday prayers in Tehran, Mashhad in the northwest, Qom in central Iran and other cities. The rallies were called for by the Islamic Council of Coordination, which runs government-approved protests, “to denounce the terrorist attack in Shiraz”, the channel said. Women clad in black chador garments or wearing headscarves joined men of all ages at the rallies, with protesters chanting “Death to America” and “Death to Israel”. The Islamic republic regularly blames its two main foes — the United States and Israel — of being behind unrest in Iran. Demonstrators also raised Iran’s national flag and held up pictures of the founder of the Islamic republic, Ayatollah Ruhollah Khomeini, and his successor, current supreme leader Ayatollah Ali Khamenei, pledging “obedience” to the latter. Iran’s ultra-conservative President Ebrahim Raisi has vowed a “severe response” to the attack on the shrine, and Khamenei also pledged that those behind the assault would be punished. Raisi also condemned “the enemies of Iran” who attempt to “divide the united ranks of the nation… through violence and terror.” The attack on the Shiraz shrine came on the same day that thousands of people paid tribute to Mahsa Amini, 40 days after her death in police custody. Amini, 22, died in police custody on September 16, three days after her arrest by the morality police in Tehran for allegedly breaching the country’s Islamic dress code for women.