Another man suspected of organizing terrorist attacks in the town of Chabahar in the south-eastern Iran, that killed 39 people, was arrested, Sistan and Baluchestan province head Ali Mohammadazade was quoted by ILNA as saying.
Earlier, a representative of the Information Ministry reported about detention of eight alleged members of terrorist attack.
Terrorist operations outside the Imam Hossein Mosque in the southeastern city of Chabahar in Iran's Sistan and Baluchestan province killed people mourning on the martyrdom anniversary of the third Imam of Shiites.
The death toll has hit 38 people, 50 people have been wounded.
Another person died in hospital. A Sunni group, Jundallah ("Army of God") took the responsibility for the crime.
Jundallah (Army of God) was created in 2003 and operates operates primarily in the Iranian province of Sistan-Baluchestan, which borders Pakistan. Jundallah uses a variety of terrorist tactics, including suicide bombings, ambushes, kidnappings and targeted assassinations. According to Tehran Jundallah connected with the U.S. and UK intelligence services.
Two suicide bombers detonated an explosive device on the night of July 16 in Zahidan in front of the mosque "Jami". The attack killed 27 people, injured 270 people, 11 of them are in critical condition.
According to Dubai TV channel Al-Arabiya, "Jundullah" group ("Warriors of Allah") took the responsibility for the attack in response to the execution of the leader of this group Abdolmalek Rigi.
The last major terrorist attack was an explosion in south-eastern Iran in October 2009 killed nearly 50 people. The organization took the responsibility for the terror act.
The province of Sistan-Baluchestan is mostly populated by Sunnis (followers of the most numerous directions in Islam). The Sunnis are a minority in Shiite Iran.