TEL AVIV/JERUSALEM/WASHINGTON, Mar. 23 (Reuters): Iran warned it would strike energy and water infrastructure across the Gulf if U.S. President Donald Trump follows through on his threat to attack its electricity grid, raising fears of mass disruption in a region heavily dependent on desalination for drinking water.

Trump set a Monday deadline of around 7:45 p.m. EDT (2345 GMT), warning late on Saturday that the United States would strike Iran’s power plants unless Tehran fully reopened the Strait of Hormuz within ‌48 hours.

The prospect of tit-for-tat strikes on civilian infrastructure further unsettled oil markets, with prices opening choppy in early Asia trading.

After more than three weeks of heavy U.S. and Israeli bombardment that officials say has sharply reduced Iran’s missile capabilities, Tehran has continued to demonstrate its ability to strike back. Air raid sirens sounded across parts of northern and central Israel, including in Tel Aviv, and the occupied West Bank overnight on Sunday, warning of incoming missiles from Iran.

Hours earlier, the Israeli military said it had completed a wave of strikes on Tehran that targeted a military base as well as weapons production and storage facilities.

At least one person was killed in an air strike on a radio station in Iran's gulf port of Bandar Abbas and Air Defenses were activated in eastern Tehran, the semi-official Mehr News agency reported early on Monday.

Trump's warning came less than a day after signalling the United States might considering winding down the conflict, even as U.S. Marines and heavy landing craft were heading to the region.

“If ⁠Iran’s fuel and energy infrastructure is attacked by the enemy, all energy infrastructure, as well as information technology...and water desalination facilities, belonging to the US and the regime in the region will be targeted pursuant to previous warnings,” Iranian military spokesman Ebrahim Zolfaqari said, according to state media.

But while attacks on electricity could hurt Iran, they would be potentially catastrophic for its Gulf neighbours, which consume around five times as much power per capita. Electricity makes their gleaming desert cities habitable, in part by powering the desalination plants that produce 100% of the water consumed in Bahrain and Qatar. Such plants use seawater to meet more than 80% of drinking water needs in the United Arab Emirates, and 50% of the water supply in Saudi Arabia.

Iran's Parliament Speaker Mohammad Baqer Qalibaf doubled down, writing on X that critical infrastructure and energy facilities in the Middle East could be "irreversibly destroyed" should Iranian power plants be attacked.

Iran's powerful Revolutionary Guards said it would also mean the shipping lane where a fifth of global oil and liquefied natural gas normally transits along Iran's southern coast would remain shut.

"The Strait of Hormuz will be completely closed and will not be opened until our destroyed power plants are rebuilt," the Guards said in a statement.

More than 2,000 people have been killed during the war the U.S. and Israel launched on February 28, which has upended markets, spiked fuel costs, fuelled global inflation fears and convulsed the postwar Western alliance.

Photo from Reuters