Gunmen in Iran opened fire inside a Shiite holy shine Wednesday evening, killing at least 15 people and wounding more than 40 others, according to official sources.

The attack occurred at the Shah Cheragh shrine in the city of Shiraz.

State media have called it a “terrorist” attack and said two of suspects have been arrested.

The Islamic State group is claiming responsibility for the attack, in two claims found online by JihadoScope.

U.N. Secretary-General Antonio Guterres condemned the attack and expressed deep condolences to the families of the victims and the people of Iran, according to a statement from his spokesman, Stephane Dujarric.

“Such acts targeting religious sites are especially heinous,” the statement said. “The Secretary-General stresses the need to bring to justice the perpetrators of this crime against civilians exercising their right to practice their religion.”

The attack took place on the same day hundreds of protesters marched to the gravesite of Mahsa Amini in northwestern Iran to mark 40 days since her death while in custody of the nation’s morality police.

Amini, a Kurdish woman, was detained by the morality police in the capital, Tehran, September 13 for allegedly wearing her head scarf — or hijab — “improperly.” The 22-year-old died while custody three days later, with police reporting she had a heart attack. Her family says she had no history of heart trouble.

Rights groups say more than 200 people have died during the protests over her death and hundreds, if not thousands, have been arrested. Analysts say the protests have become one of the most serious challenges to the Islamic Republic in its history (VOA)

• A bullet hole is seen in a shattered glass panel of the Shah Cheragh shrine in the southern city of Shiraz, Iran, Oct. 26, 2022, after gunmen attacked the Shiite holy site

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