The Iranian intelligence ministry said on Saturday that it had made 30 arrests as it dismantled a network suspected of spying for the United States on its basic infrastructure as well as its nuclear and defence research.

"Due to the massive intelligence and counter-intelligence work by Iranian intelligence agents, a complex espionage and sabotage network linked to America's spy organisation was uncovered and dismantled," a ministry statement read out on state television said.

"Elite agents of the intelligence ministry in their confrontation with the CIA elements were able to arrest 30 America-linked spies through numerous intelligence and counter-intelligence operations."

The statement said that the "network" operated in "a number of nations" under the command of "prominent intelligence officers" of the US Central Intelligence Agency.

"Under the guise of issuing student and work visas or permanent residency ... they tried to trick citizens into spying for them," the statement said.

The agents sought information from "universities and scientific research centres and in the fields of nuclear energy, aerospace, defence, biotechnology ... detailed data on gas and oil pipelines, telecommunication networks, airport and customs, and the security of the nation's banking systems," it added.

The statement said that the CIA officers handling the network operated out of "US embassies and consulates in a number of nations namely, the United Arab Emirates, Turkey and Malaysia."

In the course of the operation, "not only has the heavy offensive by the Central Intelligence Agency been neutralised but 42 CIA officers in different nations have been accurately identified by our intelligence," the statement added.

Iran has claimed several times in the past to have dismantled spy networks working for the United States or Israel.

In January, the intelligence ministry said it had arrested "spies and terrorists" linked to Israel's Mossad overseas intelligence agency whom it accused of being behind the killing last year of Iranian nuclear scientist Masoud Ali Mohammadi.

Iran has also accused the United States and Israel of carrying out cyber-attacks against its infrastructure, including its nuclear facilities.

It was hit by a computer worm dubbed Stuxnet last year which was reportedly designed to target its nuclear programme and then mutated and infected at least 30,000 pieces of computerised industrial equipment in the following months.

In December, Iran implicitly admitted its uranium enrichment plant in the central city of Natanz, which is regularly inspected by the UN nuclear watchdog, had been a victim of the worm.

Last month, civil defence chief Gholam Reza Jalali revealed that Iran had been hit by a new virus dubbed Stars although he did not say what kind of equipment it was targeting.

Computer security firm Symantec said in November that Stuxnet might have been designed to disrupt the motors that power gas centrifuges used to enrich uranium -- the most controversial aspect of Iran's nuclear programme.

Western governments suspect that Iran is seeking to develop an atomic weapons capability under cover of its civil nuclear programme, an ambition it strongly denies.