Iran has admitted launching a series of cyber attacks against what it described as its "enemies".
Hackers working for the Revolutionary Guard's paramilitary Basij section targeted websites, a state-owned newspaper reported in a rare admission that the country is involved in internet warfare.
The report followed an announcement in January that Iran had formed its first cyber police unit in an attempt to gain an edge in the digital world.
The internet has also been a key outlet for Iran's opposition since the disputed 2009 presidential election. In addition, Iran has been trying to boost its web defences after a virus got into computers involved with the country's controversial nuclear programme.
General Ali Fazli, acting commander of the Basij, said the cyber army consisted of university teachers, students and clerics.
He said its attacks were a retaliation for similar ones on Iran. He gave were no further details about the possible targets or the time of the attacks.
"As there are cyber attacks on us, so is our cyber army of the Basij, which includes university instructors and students, as well as clerics, attacking websites of the enemy," General Fazli said. "Without resorting to the power of the Basij, we would not have been able to monitor and confront our enemies."
In February, Revolutionary Guard chief General Mohammad Ali Jafari signalled that the force supports the cyber army, describing it as a "defensive, security, political and cultural need for all countries".
Iran has been seeking to master the digital world as a crucial step to prepare for what it calls "soft war," which includes fighting against cyber attacks such as the Stuxnet computer worm that Iran said was aimed at sabotaging its uranium enrichment programme.