The US is investigating the leak of classified information about Israel's plans to strike Iran

The United States is investigating the leak of secret intelligence on Israel's plans to strike back at Iran, CNN reports, citing its own sources.

The leak is "deeply troubling," a US official told CNN.

The documents, dated October 15 and 16, reportedly began circulating online on Friday, having been posted on the Middle East Spectator Telegram channel.

The documents are marked "top secret" and have notations indicating that they are intended only for viewing by the United States and its five allies: Australia, Canada, New Zealand and the United Kingdom.

The leaked documents describe the preparations Israel appears to be making to strike Iran.

One of the documents, said to have been compiled by the National Geospatial-Intelligence Agency, says the plans include the transfer of Israeli munitions.

Another document, said to have been obtained by the National Security Agency, describes Israeli air force exercises using air-to-surface missiles, which are also believed to be being prepared to strike Iran.

One of the documents also states that Israel has always refused to publicly confirm that the country has nuclear weapons. The document says the US has seen no indication that Israel intends to use nuclear weapons against Iran.

An official source of the TV channel said that the investigation is finding out who had access to the alleged Pentagon document. In the event of any such leak, the FBI would automatically launch an investigation in conjunction with the Pentagon and US intelligence agencies.

"If it is true that Israeli tactical plans to respond to the October 1 attack by Iran were leaked, it is a serious breach," said Mick Mulroy, former deputy secretary of defense for Middle East affairs and retired CIA officer.

According to Mulroy, “future coordination between the US and Israel may also be called into question. Trust is a key component of a relationship, and depending on how the information is leaked, that trust can be undermined."