Iran said on Monday it had exposed a large cyber espionage network it alleged was run by the U.S. Central Intelligence Agency (CIA), and that several U.S. spies had been arrested in different countries as the result of this action.

U.S.-Iran tensions are growing following accusations by U.S. President Donald Trump's administration that Tehran last Thursday attacked two oil tankers in the Gulf of Oman, a vital oil shipping route. Iran denies having any role.

The secretary of Iran's Supreme National Security Council, Ali Shamkhani, said on Monday: "One of the most complicated CIA cyber espionage networks that had an important role in the CIA's operations in different countries was exposed by the Iranian intelligence agencies a while ago and was dismantled."

"We shared the information about the exposed network with our allies that led to the identification and arrest of CIA intelligence agents," Shamkhani was quoted as saying by the state broadcaster IRIB.

He did not specify how many CIA agents were arrested and in what countries.

Shamkhani said without elaborating that some information about the case had been released by the United States, so Iran could now publish the information for the sake of public awareness.

Trump last year withdrew the United States from a 2015 international nuclear deal with Iran, and is ratcheting up sanctions seeking to end Iran's international sales of crude oil and strangle its economy.

The United States has deployed a carrier strike group and bombers to the and announced plans to deploy 1,500 troops to the Middle East, prompting fears of a conflict.