The allegations come ahead of an Iran-US meeting on Iraq

The intelligence ministry said it had "succeeded in uncovering, identifying and striking blows" at infiltrators organised by those forces.

The statement said the networks had been detected in western, south-western and central parts of Iran.

The allegations come two days before the Iran and US ambassadors meet in Baghdad to discuss the crisis in Iraq.

The statement, which was broadcast on state-run television, gave no further details.

"These spy networks were operating under the guidance of the occupiers' intelligence services and with the support of some influential Iraqi groups and factions," it said.

The White House said it did not confirm or deny allegations about intelligence matters.

"We urge Iran to play a positive role in Iraq... and stop blaming everyone else for problems they are only bringing on themselves," a White House spokeswoman is quoted as saying by the Associated Press news agency.