US President Donald Trump said the latest strikes were conducted in honour of the American soldiers killed, declaring that the US had hit Iranian targets "very hard again."

US Central Command said the strikes targeted Iranian military command centres, air defence systems, missile and drone launch sites, coastal surveillance facilities and communications networks.

Iranian state media reported explosions in southern and northwestern Iran, while Tehran said a nuclear power plant construction site in the southwest was struck during the attacks.

A ship caught fire in the Strait of Hormuz as tensions disrupted one of the world's busiest oil shipping routes. Iran's Revolutionary Guard later claimed it was targeting tankers in the strategic waterway.

Iran launched missiles toward Jordan, prompting Jordan, Bahrain and Kuwait to activate air defence systems amid fears that the conflict could spread across the Middle East.

Israel warned that Iranian missiles aimed at Jordan could spill into Israeli territory, raising concerns of the conflict expanding further after weeks without air raid sirens.

Jordan's military said it intercepted several Iranian missiles without casualties or damage, while the government formally protested to Iran over the attacks.

Kuwait said one of its power and water desalination plants was attacked for the second time in two days, triggering fires but leaving the national power grid stable.

As fighting intensifies and shipping through the Strait of Hormuz slows, Brent crude prices climbed above USD 90 per barrel, adding pressure to global energy markets.