At least 10 suspects have been arrested by security forces over Sunday's attack on a popular shrine in southern Iran's Shiraz city, which killed one and injured nine others.
The semi-official Tasnim News Agency in a report on Monday said the interrogation of one of the attackers who was apprehended by security forces following the attack continues.
Earlier in the day, Iran's state media cited officials as saying that four suspects had been arrested.
The attack took place at around 7 p.m. local time (1530GMT) after two heavily armed assailants opened indiscriminate fire at the entrance of the Shah Cheragh shrine.
Nour News, which is affiliated with Iran's top security body, said two men were involved in the attack, one of whom was carrying a Kalashnikov weapon and got arrested while the other managed to flee.
Both provincial officials and the shrine officials confirmed one death in the incident. Earlier, local media, including state and semi-state news agencies, had put the death toll at four.
Hours after the attack, President Ebrahim Raisi directed the Interior Ministry and the provincial governor's office to "immediately identify all the perpetrators" and refer them to the judiciary.
Health officials in Shiraz told state TV that at least nine people were injured in the attack, who are presently undergoing treatment at various hospitals and are in stable condition.
Iran's Foreign Ministry spokesman Nasser Kanaani termed it a "criminal act," and said the "terrorists are trying to take revenge" from the Iranian nation for the "heavy blows" military forces have inflicted on them.
Meanwhile, Iran's Parliament Speaker Baqar Qalibaf said "fomenting insecurity (in Iran) and disrupting people's daily lives has been a permanent project of enemies."
Interior Minister Ahmad Vahidi, who visited the shrine on Monday, said "the silence of human rights advocates promotes terrorism," noting that when the shrine was attacked in October last year, human rights bodies "remained silent."
"Those who cooperated, participated and supported in this work will be severely punished and the enemies of the nation will not be spared," he told reporters in Shiraz.
The identity of the attacker, who has been arrested, has not been revealed yet, but some local news agencies claimed he is an Afghan national from northern Afghanistan's Badakhshan province.
Iran's state TV cited BBC as saying on Sunday night that the Daesh, or ISIS terrorist group, claimed responsibility for the attack.
The 12th century shrine, which houses the grave of a revered Shia scholar, is a popular destination for local and foreign tourists in southern Fars province.
At least 13 people were killed and 40 others injured after an armed attacker opened indiscriminate fire inside the shrine last October. It was also claimed by Daesh.
