The largest hospital in southern Israel has been hit by an Iranian ballistic missile that sent patients and staff into a frenzied evacuation

The Soroka Medical Center was one of four locations across Israel reportedly struck by Iran on Thursday.

The facility, which has more than 1000 beds, and surrounding apartment buildings in the city of Be’er Sheva sustained damage, officials in the country said.

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“We are currently assessing the damage, including injuries,” said a spokesperson for center, which is described as one of the country’s leading health facilities.

“We ask that you not come to the hospital now.”

The spokesperson said there was “extensive damage in various areas”.

Israel described the hit as coming from an “indiscriminate Iranian ballistic missile”, and search and rescue teams have been sent to the affected sites.

“A baby in intensive care. A mother by their bedside. A doctor rushing between beds. An elderly resident in a nursing home. These were some of the targets of Iran’s missile attacks on Israeli civilians this morning,” Israel’s President Isaac Herzog said.

Iran’s state news agency, IRNA, reported Iran had been targeting an intelligence headquarters adjacent to the hospital, and claimed the hospital sustained only minor damage from a blast shockwave.

It came as Israel acted on a warning that it would attack Iran’s Arak heavy water reactor.

A report on Iranian state television said there was “no radiation danger whatsoever” and the facility had already been evacuated before the attack.

The Arak heavy water reactor is 250km southwest of Tehran.

Heavy water helps cool nuclear reactors, but it produces plutonium as a byproduct that can potentially be used in nuclear weapons.

Iran agreed under its 2015 nuclear deal with world powers to redesign the facility to relieve proliferation concerns.

The International Atomic Energy Agency has been urging Israel not to strike Iranian nuclear sites.

Israel’s airstrike campaign has targeted Iran’s enrichment site at Natanz, centrifuge workshops around Tehran and a nuclear site in Isfahan.

The latest attacks came as US President Donald Trump kept the world guessing about his response.

Trump told reporters he will not say whether he has decided to order a US strike on Iran, a move that Iranian officials warned anew would be greeted with stiff retaliation if it happens.

“I may do it. I may not do it. I mean, nobody knows what I’m going to do,” he said outside the White House.

Trump said Iranian officials had reached out about negotiations, including a possible meeting at the White House but “it’s very late to be talking”, he said.

“Unconditional surrender, that means I’ve had it.”

Asked for his response to Iranian Supreme Leader Ayatollah Ali Khamenei rejecting the idea of surrendering, Trump said: “I say, good luck.”

Trump has veered from proposing a swift diplomatic end to days-long war to suggesting the US might join it.

A source familiar with internal discussions said Trump and his team were considering options that included joining Israel in strikes against Iranian nuclear installations.

Defense Secretary Pete Hegseth told a Senate committee that the Pentagon was prepared to execute any order given by Trump.

‘We will continue to strike’

People jammed highways out of the capital Tehran, a city of 10 million people, as residents sought sanctuary from intensified Israeli air strikes.

Israel’s military said 50 Israeli jets struck about 20 targets in Tehran overnight, including sites producing raw materials, components and manufacturing systems for missiles.

It advised Iranians to leave parts of Tehran for their own safety while it bombed targets.

“As we promised — we will continue to strike at symbols of governance and hit the ayatollah regime wherever it may be,” Israel Defence Minister Israel Katz said.

Israeli strikes on Iran have killed at least 639 people and wounded 1329 others, according to Washington-based group Human Rights Activists.

- With AAP