According to the Ministry of Intelligence, a suspected attacker is a Tajik national who entered Iran illegally last month.
Iranian authorities say they have identified the suspected ringleader who made the bombs for the two Jan. 3 bombings in the southeastern city of Kerman that killed more than 90 people, state media reported.
On Thursday, the Intelligence Ministry said the main suspect who planned the bombings was a Tajik citizen known by his pseudonym Abdollah Tajiki, IRNA news agency reported.
A ministry statement said he entered Iran via the southeastern border in mid-December and left the country two days before the attack after detonating the bombs.
The armed group ISIL (ISIS) claimed responsibility on January 4 for the attack in Kerman, about 820 km (510 miles) southeast of the capital Tehran, on a monument to commander-in-chief Qassem Soleimani.
Soleimani, the head of the Islamic Revolutionary Guard Corps' (IRGC) elite Quds Force, was killed in a drone strike in Iraq in 2020 ordered by then US President Donald Trump.
On Thursday, authorities said the death toll from the attack had risen to 94, including 14 Afghan nationals. More than 280 people were injured.
According to IRNA, 35 people with alleged links to the bombings have been arrested in several provinces so far.
According to the ministry, a bomber first detonated its explosives at the ceremony in Kerman, then another attacked 20 minutes later as rescue workers and other people tried to help those wounded in the first blast.
People gather at the site of the explosions in Kerman [File: West Asia News Agency/Reuters]Last week, as funerals were held in Kerman, Iranian President Ebrahim Raisi vowed to retaliate for the attack, telling Tehran's enemies that “our armed forces will decide the place and time of action.”
The United Nations, the European Union and several countries including China, Saudi Arabia, Jordan and Iraq condemned the bombings.
Tehran frequently claims that both Israel and the US support anti-Iran armed groups that have been involved in previous attacks.
In 2022, ISIL claimed responsibility for an attack on an Iranian Shiite shrine that killed 15 people.
Previous attacks attributed to ISIL include the 2017 twin bombings of Iran's parliament and the mausoleum of Ayatollah Ruhollah Khomeini, the republic's founder.