Washington and its allies believe a major attack on Israel by Iran is imminent and may be launched in the coming days, Bloomberg reported on Wednesday, citing officials familiar with the intelligence.

According to US and Israeli sources, Iran’s retaliatory attack has become a matter of when, not if, the officials said, warning that the expected assault “may not necessarily come from Israel’s north”.

The Islamic Republic’s response to the killing of an Iranian general in Syria on 1 April, which Tehran has blamed on the Jewish state, could involve precision missiles being launched at Israel, according to the sources.

Israel’s allies have reportedly been told that government and military structures may be targeted but civilian facilities are not expected to be. US officials were said to be helping Israel prepare for the attack.

Jerusalem also informed allies it is waiting for Iran to attack before launching a ground offensive to clear out the remaining 3,000 Hamas terrorists in Gaza’s southernmost city of Rafah, Bloomberg reported.

Israel has not officially taken responsibility for the attack in Damascus which killed Brig. Gen. Mohammad Zahedi, but four officials told The New York Times last week that Jerusalem ordered the strike.

Senior sources in the Iranian regime told Reuters on 4 April that Tehran would provide a “serious response” to the killing of Zahedi, suggesting however that it would seek to avoid a direct clash with Israel and the United States.

An Iranian retaliatory attack could include “a swarm of Shahed loitering drones and cruise missiles,” according to US intelligence, CBS News reported on 5 April.

The Israel Defence Forces has been placed on high alert, resulting in combat soldiers’ weekend leaves being cancelled and the military calling up additional reserve soldiers to the IDF Aerial Defence Array.

Israeli Foreign Minister Israel Katz warned on Tuesday that Israel will respond in kind should Iran launch a direct attack against it.

“If Iran attacks from its territory, Israel will respond and attack in Iran,” tweeted Katz. The minister tagged Iran’s Supreme Leader Ali Khamenei in the X post.

A Western security official told the London-based Arabic-language newspaper Elaph that Israel had conducted secret air force training in recent days, involving long-distance flights and rehearsals of strikes on sensitive sites in Iran that may be tied to that country’s nuclear project.