A gunman who killed 15 people at a major Shiite holy site in southern Iran this week has died in hospital, Iranian media reported.

Authorities have not disclosed details about the attacker, who died in hospital in the southern city of Shiraz on Saturday from injuries sustained during his arrest, according to the semi-official Fars and Tasnim news agencies.

It is unusual for authorities not to elaborate on the gunman’s nationality or provide any details about him after Wednesday’s attack at Shah Cheragh in Shiraz, the second-holiest Shiite shrine in Iran.

The attack was claimed by the so-called Islamic State militant group, but Tehran has sought to blame it on protests that have rocked the country since the death on September 16 of Mahsa Amini in the custody of the country’s morality police.

The protests first focused on the state-mandated hijab, or headscarf, for women but quickly grew into calls for the downfall of Iran’s theocracy itself.

At the funeral for victims of the shooting in Shiraz, the chief of the Revolutionary Guard, General Hossein Salami, called on Iranians to stop protesting.

“Today is the end of the riots. Do not go to the streets any more,” he said on Saturday. “We are telling our youth, the minority of you who have been deceived, stop the evil acts.

“This ominous sedition will bring no happy ending to you. Do not ruin your future.”

At least 270 people have been killed and 14,000 arrested in the protests that have swept more than 125 Iranian cities, according to the group Human Rights Activists in Iran.

Iranian officials have blamed protesters for paving the way for the assault on the shrine in Shiraz, but there is no evidence linking extremist groups to the widespread, largely peaceful demonstrations engulfing the country.

Security forces have violently cracked down on demonstrations with live ammunition, anti-riot pellets and tear gas.

IS claimed the attack on the shrine — its first such claim in Iran in four years. Iran’s religious sites have previously been targeted by IS and other Sunni extremists.

The Iranian government has repeatedly alleged that foreign powers have orchestrated the protests, without providing evidence.

The protests have become one of the most serious threats to Iran’s ruling clerics since the 1979 Islamic Revolution.