Iran has arrested 26 foreign nationals over their alleged involvement in a deadly attack claimed by the militant Islamic State (IS) group on a Shia Muslim shrine, the intelligence ministry said on Monday.

At least 13 people were killed on October 26 in an armed attack on the Shah Cheragh mausoleum in Shiraz, according to an official toll.

“The intelligence ministry has identified and arrested all agents involved in the terrorist operation in Shiraz,” said a statement published on the ministry’s website.

According to the statement, the 26 “takfiri terrorists” are from Azerbaijan, Tajikistan and Afghanistan.

“These terrorists were arrested in the provinces of Fars, Tehran, Alborz, Kerman, Qom and Razavi Khorasan”, as well as along Iran’s “eastern border”, the ministry added.

The shooting at the shrine — considered the holiest Shia site in southern Iran — came on the same day that thousands of people across the country paid tribute to Mahsa Amini, 40 days after her death in police custody.

Amini, 22, died 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.

The perpetrator of the attack in Shiraz, identified by the intelligence ministry as Sobhan Komrouni, died of wounds sustained while he was being arrested.The ministry said he was “a Tajik national” known as Abu Aisha.

It added that the main coordinator of attacks in Iran, an Azeri national, was also arrested, having entered the country through Tehran’s international airport from Baku.

He had been in contact with an IS network abroad after arriving in Tehran, it added.

On October 31, the ministry announced that several others had been arrested, including an “operational support element” identified on Monday as Mohammed Ramez Rashidi, an Afghan national.

Remarks last month by President Ebrahim Raisi appeared to link the Shiraz attack, one of the country’s deadliest in years, with the protests and “riots” following Amini’s death.

He had vowed “a severe response” to the attack.