CAIRO — Iranian missiles struck two communities in southern Israel late Saturday, leaving buildings shattered and dozens injured in dual attacks not far from Israel’s main nuclear research center, while President Donald Trump warned the U.S. will “obliterate” Iranian power plants if it doesn’t fully open the Strait of Hormuz within 48 hours.

The developments signaled the war was moving in a dangerous new direction at the start of its fourth week.

Trump — who is facing increasing pressure at home to secure the strait as oil prices soar — issued the ultimatum in a social media post while he spent the weekend at his Florida home.

Trump said he’s giving Iran 48 hours to open the vital waterway or face a new round of attacks. He said the U.S. would destroy “various POWER PLANTS, STARTING WITH THE BIGGEST ONE FIRST!”

The Strait of Hormuz, which connects the Persian Gulf to the rest of the globe’s oceans, is a critical pathway for the world’s flow of oil. Attacks on commercial ships and threats of further strikes have stopped nearly all tankers from carrying oil, gas and other goods through the passage. That’s also led to cuts in output from some of the world’s largest producers, because their crude has nowhere to go.

The Iranian strikes in Israel came after Tehran’s main nuclear enrichment site at Natanz was hit earlier in the day.

Israel’s military said it was not able to intercept missiles that hit the southern cities of Dimona and Arad, the largest near the center in Israel’s sparsely populated Negev desert. It was the first time Iranian missiles penetrated Israel’s air defense systems in the area around the nuclear site.

“If the Israeli regime is unable to intercept missiles in the heavily protected Dimona area, it is, operationally, a sign of entering a new phase of the battle,” Iran’s Parliament Speaker Mohammad Bagher Ghalibaf said on X before word of the Arad strike spread.

Israeli Prime Minister Benjamin Netanyahu said more emergency crews were being sent to the scene.

“This is a very difficult evening,” he said.

Rescue workers said the direct hit in Arad caused widespread damage across at least 10 apartment buildings, three of them badly damaged and in danger of collapsing. At least 64 people were taken to hospitals.

Dimona is about 20 kilometers (12 miles) west of the nuclear research center and Arad around 35 kilometers (22 miles) north.

Israel is believed to be the only Middle East nation with nuclear weapons, though its leaders refuse to confirm or deny their existence. The U.N. nuclear watchdog said on X it had not received reports of damage to the Israeli center or abnormal radiation levels.

A dangerous new direction in the war

“The war is not close to ending,” Israel’s army chief, Gen. Eyal Zamir, said earlier in the day.

Iran also targeted the joint U.K.-U.S. Diego Garcia military base in the Indian Ocean about 2,500 miles (4,000 kilometers) away, suggesting that Tehran has missiles that can go farther than previously acknowledged — or that it had used its space program for an improvised launch.

The U.S. and Israel have offered shifting rationales for the war, from hoping to foment an uprising that topples Iran’s leadership to eliminating its nuclear and missile programs and its support for armed proxies. There have been no signs of an uprising, while internet restrictions limit information from Iran.

The war’s effects are felt far beyond the Middle East, raising food and fuel prices.

It is not clear how much damage Iran has sustained in the U.S. and Israeli strikes that began Feb. 28 — or even who is truly in charge. Supreme Leader Ayatollah Mojtaba Khamenei has not been seen in public since being named to the role.

Israel had denied responsibility for attack on Natanz

Israel earlier Saturday denied responsibility for the strike on the Natanz nuclear facility, nearly 220 kilometers (135 miles) southeast of Tehran. The Iranian judiciary’s official news agency, Mizan, said there was no leakage.

The International Atomic Energy Agency has said the bulk of Iran’s estimated 970 pounds (440 kilograms) of enriched uranium is elsewhere, beneath the rubble at its Isfahan facility. It said on X it was looking into the strike.

The Pentagon declined to comment on the strike on Natanz, which was also hit in the first week of the war and in the 12-day war last June. Russian Foreign Ministry spokesperson Maria Zakharova said such strikes posed a “real risk of catastrophic disaster throughout the Middle East.”

Iran retaliated hours later.

US can use Diego Garcia base to protect Strait of Hormuz

U.K. officials did not give details of the strike that targeted the Diego Garcia base Friday, which was unsuccessful. Britain’s Ministry of Defense described Iran as “lashing out across the region.”

It’s unclear how close the missiles came to the island. Iran previously asserted that it has limited its missile range to below 2,000 kilometers (over 1,200 miles).

But military experts said Iran may have used its space launch vehicle for an improvised firing. “If you’ve got a space program, you’ve got a ballistic missile program,” said Steve Prest, a retired Royal Navy commodore.

Israel’s army chief, however, said Iran had fired “a two-stage intercontinental ballistic missile.” There was no statement from Iran.

Britain has not participated in U.S.-Israeli attacks but has allowed U.S. bombers to use its bases to attack Iran’s missile sites. On Friday, the U.K. government said bombers could use Diego Garcia to attack sites used to target ships in the Strait of Hormuz.