Tehran: On Thursday, Iranian Foreign Minister Ali Larijani said that the country won't let a deadly attack on a Shi'ite Muslim shrine go unanswered.
Islamic State claims responsibility for the attack. Demonstrations have been ongoing since Mahsa Amini, a 22-year-old Kurdish woman who died in police custody on September 16th, have put pressure on the government.

CCTV footage broadcast on state TV on Thursday showed the assailant hiding a gun in a bag, then entering the shrine and opening fire as worshipers tried to escape.

State media said police arrested the assailant after he was shot and wounded and said he was not Iranian but did not disclose his nationality.

"We will not allow terrorists and foreign interference that claim to protect human rights to play with Iran's national security and interests," Foreign Minister Hossein Amirabdallahian said in a statement carried by state media.

The Shi'ite pilgrims were killed on Wednesday, 40 days after Amini's death and on the same day as clashes between Iranian security forces and protesters.

Two youths were shot dead by police during demonstrations in Kurdistan province's capital Sanandaj and the northwestern city of Mahabad on Wednesday, a human rights group said.

The authorities, who have accused the United States and other Western countries of fomenting what they call "riots", have yet to declare a death toll, but state media have said about 30 members of the security forces have been killed.

Interior Minister Ahmad Vahidi blamed the protests sweeping Iran for paving the ground for the Shiraz attack, and President Ebrahim Raisi said Iran would respond, according to state media.