"We could identify five spy networks, 20-people strong, and arrest them," ISNA news agency said, quoting the intelligence chief of Kermanshah, which has a substantial Kurdish minority and borders Iraqi Kurdistan.

"The spies belonging to these gangs have internal and foreign elements that were bribed and briefed by the enemy's intelligence services for economic, military, political, cultural, and social aims inside the country," he said.

The official added that Iran had arrested three members of Pejak -- the Kurdish militant party linked to Turkey's outlawed Kurdistan Workers' Party (PKK) -- over a May 2006 bomb explosion in government offices in Kermanshah that injured seven.

"The terrorist group of Pejak was behind the bombing in Kermanshah directed by the system's sworn enemies and with the aim of inciting fear and disrupting people's security.

"Three members of Pejak were arrested with more than ten kilos of explosives," the official said, describing the United States and Israel as the Islamic republic's sworn enemies.

The attacks came amid tensions between Iraqi Kurds and Iran and Turkey, both of which have Kurdish minorities and have been battling separatist militants from the PKK and its offshoots.