Iranian authorities have arrested 35 people in relation to the January 3 attacks in the southeastern city of Kerman, the Intelligence Ministry said on Thursday, according to the semi-official Tasnim news agency.
The ministry said it had identified one of the two suicide bombers as a national of Tajikistan, who entered Iran illegally on December 19.
More information will be released at a later date about the second suicide bomber, the ministry said, adding that the arrests had been carried out in several Iranian provinces.
The IS claimed responsibility on January 4 for the attack that killed nearly 100 people and wounded 284, at a memorial for top commander Qassem Soleimani.
Tehran has vowed revenge for the bloodiest such attack since 1979.
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