DUBAI, United Arab Emirates (AP) — Students clashed during a memorial ceremony for the victims of a deadly attack at a major Shiite holy site in southern Iran, the country's semi-official news outlet said Sunday.

The Tasnim news agency reported that some groups attacked a gathering in a branch of Azad University in Tehran. Several students were injured, it said, quoting witnesses as saying some students had knives in their hands. Tasnim also said an unidentified person fired tear gas during the clash and then disappeared into the crowd. The report did not elaborate on how many people were injured in the clash.

On Sunday, hardline students in several universities across the country gathered to commemorate a deadly attack by a gunman who killed 13 people, including women and children, at Shah Cheragh mosque Wednesday. Thirty people were wounded.

The militant Islamic State group claimed responsibility for the shooting.

The nationwide unrest — sparked by the Sept. 16 death of Mahsa Amini in the custody of the country’s morality police — has rocked the Islamic Republic for a month and a half. Amini died after being detained for allegedly violating the country’s strict Islamic dress code for women.

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.

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

Since October 24, the country’s authorities started hearing the cases of at least 900 protesters charged with “corruption on earth” — a term often used to describe attempts to overthrow the Iranian government that carries the death penalty. Judicial officials have announced charges against hundreds of people in Tehran and other provinces as they seek to quash dissent.