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.


Hurricane Melissa hits Cuba hours after devastating Jamaica
Trump says Gaza ceasefire holds, Israel has right to hit back if attacked
South Korea welcomes Trump with its highest award, a golden crown and ketchup
Ex-Philippines president Duterte appeals ICC jurisdiction ruling
Cyclone Montha lashes India's east coast; kills one
At least 9 killed, 5 missing in central Vietnam floods
Arab League warns of war escalation, Israeli occupation practices
Israel's Netanyahu orders 'powerful attacks' in Gaza
