Israel has been forced to delay a potential retaliatory attack on Iran after details of the planning were leaked from the Pentagon, Paralel.Az reports citing the UK’s Times newspaper.

According to the report, citing an intelligence source with knowledge of Israeli deliberations, Israel is worried that even though no potential targets were named in the leak, the details provided could help Iran predict certain patterns of attack.

The Times says Israel has developed an alternative plan but needs to war-game them before proceeding.

“The leak of the American documents delayed the attack due to the need to change certain strategies and components,” the source says. “There will be a retaliation, but it has taken longer than it was supposed to take.”

Marked top secret, the documents first appeared online Friday on the Telegram messaging app and quickly spread among Telegram channels popular with Iranians.

The FBI is investigating the leak.

The Islamic Republic has been bracing for an Israeli reprisal after its latest direct attack on Israel, in which it fired 200 ballistic missiles that sent most of Israel to bomb shelters on October 1, killed a Palestinian man in the West Bank, and caused minor damage in residential areas and at military bases.

Iran said the missile assault came in response to strikes in Lebanon that killed the top leadership of the Iran-backed Hezbollah terror group and a July blast in Tehran that killed Hamas politburo head, Ismail Haniyeh.