Story highlights Iran says the men were providing classified material to foreign intelligence agencies

There were no comments from Israeli or U.S. officials

One rights group says Iran hanged 488 people in one 12-month period

Iran still holds former U.S. Marine it says was spying for the CIA

Two men who the Iranian government said worked as spies for Israel and the United States were hanged Sunday morning, according to Iranian state news outlet Press TV.

The men were identified as Mohammad Heidari and Kourosh Ahmadi. Press TV said Heidari provided classified information to Mossad, the Israeli intelligence agency, and Ahmadi had been convicted of providing the CIA with intelligence.

There were no details on when the men were arrested or when they were tried. The hangings occurred at dawn, the report said.

Israeli officials didn't comment on the report.

The U.S. State Department acknowledged seeing the reports but had no comment. The CIA didn't immediately respond to CNN's request for comment.

JUST WATCHED Uncertainty in Iranian elections Replay More Videos ... MUST WATCH Uncertainty in Iranian elections 01:38

The advocacy group Human Rights Activists News Agency, based in Iran, estimated in 2012 that there were 488 hangings in the prior 12 months. About 12% of those were public executions, the group said, according to a State Department report.

One person hanged in 2012 was Majid Jamali Fashi, who was convicted of killing an Iranian scientist. Iran said Israel paid him $120,000 to kill elementary-particle physicist Massoud Ali-Mohammadi.

Iran also has blamed the United States and the United Kingdom for attacks against nuclear scientists.

Iran's enrichment of uranium has been one of the most contentious issues in nuclear talks between Iran and the so-called P5+1 countries -- the United States, France, Britain, China, Russia and Germany. Iran has denied that it aims to build a nuclear bomb, claiming its nuclear program is for energy and medical use.

Iran also holds a former U.S. Marine, Amir Hekmati, who was detained in August 2011 while visiting his grandmother. Iranian authorities accused him of spying for the CIA, a charge his family and the Obama administration deny.

Originally he was sentenced to death during a closed-door trial, but that conviction was overturned, and the Arizona native awaits a new trial.