Tehran: In an attempt to conduct free and fair polls, Iran has arrested an unidentified number of spies who allegedly sought to carry out US plans and disrupt an upcoming parliamentary election, Intelligence Minister Heydar Moslehi said on Monday.

"Those arrested were after carrying out American plans and operations to disrupt the parliamentary election using cyber space and social networks," Moslehi told reporters after a Cabinet session, state media reported.

Moslehi did not say when or how many people were arrested, nor did he reveal their nationalities.

But he said they were also in contact with people abroad, through the internet, as Iran braces to hold a legislative election on March 2, its first poll since the disputed 2009 presidential election.

Iranian officials have on a number of occasions announced the arrest of suspected spies for the United States, but provided little information to substantiate the claimed detentions or allegations in most cases.

The report coincides with the trial in Iran of a former US Marine of Iranian descent, Amir Mirzai Hekmati, after he was accused of working on behalf of the US Central Intelligence Agency to infiltrate the Iranian intelligence ministry.

Tehran frequently accuses the United States of seeking to undermine its regime through covert operations.

The United States has had no diplomatic relations with Iran since shortly after the 1979 Islamic revolution that overthrew the pro-Western shah.