The unnamed source quoted by the station did not say when and where the six had been arrested.
More than 40 people including senior commanders of the Islamic Republic's Revolutionary Guards were killed in a suicide bombing in Iran's southeastern province of Sistan-Baluchestan, bordering, Pakistan on Oct. 18.
Iran, a predominantly Shi'ite Muslim country with Sunni minorities, accused Pakistan of backing the Sunni rebel group that claimed responsibility for the attack.
Iran has also accused Britain and the United States of being involved. London, Washington and Islamabad all deny involvement.
Iran has urged Pakistan to hand over the leader of the Jundollah, or "Soldiers of God", insisting it has bases in Pakistan.
Several Guards commanders had urged the Iranian authorities to allow the Guards to confront terrorists inside Pakistan.
Jundollah, which accuses the government of discrimination against Sunnis, has been blamed for many deadly incidents over the last few years. It reportedly claimed the bombing of a mosque in Sistan-Baluchestan in May that killed 25 people.
The Guards, seen as fiercely loyal to Supreme Leader Ayatollah Ali Khamenei, handle security in border areas. Their power and resources have increased since the election of hardline President Mahmoud Ahmadinejad in 2005.
(Writing by Parisa Hafezi; Editing by Kevin Liffey)
