WASHINGTON - The United States said it had destroyed the headquarters of Iran's powerful Revolutionary Guard force, but also announced the first US fatalities in the war to overturn the Iranian government.
US Central Command, or CENTCOM, announced the Guard headquarters destruction in a statement on X accompanied by video of missiles blasting from a US Navy ship, then pulverizing an urban compound.
"America has the most powerful military on earth, and the IRGC no longer has a headquarters," CENTCOM said.
As missiles continued to rain on Tehran, President Donald Trump said the war could go on for a month, telling the Daily Mail that "it's always been a four-week process."
The US-Israeli campaign began Saturday with bombing that killed Iran's supreme leader. Iran has retaliated with missile and drone attacks on countries across the Middle East, with explosions reported in Saudi Arabia, the UAE, Qatar, Bahrain, Oman and Israel.
Iran is publicly defiant in the face of the US and Israeli bombardment, but Trump told The Atlantic magazine that its surviving leaders "want to talk" -- although he was vague about details.
The Pentagon reported that "three US service members have been killed in action and five are seriously wounded", adding several others had sustained minor shrapnel injuries and concussions.
"Major combat operations continue and our response effort is ongoing," it said.
Underlining the political risks back home for Trump, the 79-year-old Republican took hours to react to the US deaths, before telling NBC News: "We expect casualties, but in the end it's going to be a great deal for the world."
Loud explosions shook Tehran on Sunday.
Iran's Revolutionary Guards announced its own "large-scale" attack as it launched missiles and drones at installations around the Gulf.
An attack on the central Israeli city of Beit Shemesh killed at least nine people, with others still missing, authorities said.
Ali Larijani, the powerful head of Iran's Supreme National Security Council, declared: "Today we will hit them with a force that they have never experienced before."
And Iran's President Masoud Pezeshkian declared the killing of Iran's supreme leader Ayatollah Ali Khamenei a "declaration of war against Muslims."
He warned: "Iran considers it its legitimate duty and right to avenge the perpetrators and masterminds of this historic crime."
But Israel described Khamenei's death as a "first step", and military spokesman Lieutenant Colonel Nadav Shoshani boasted that the joint operation "eliminated 40 senior commanders, including Khamenei, in one minute."