Washington DC - The US military launched "powerful" strikes on Iran on Thursday, in retaliation for Tehran's attacks targeting US bases in Jordan as the Middle East war reignited and again drew in the Islamic republic's proxies.

The first strikes after a nearly week-long lull in fighting dashed hopes of a return to negotiations.

"The strikes are a powerful response to yesterday's attempted Iranian attacks on US forces based in the Middle East", US Central Command said.

Saudi Arabia and the US also announced strikes Wednesday on militant bases in Iraq, while US ally Israel accused Iran-backed Hezbollah of a truce violation.

Iran War US slaps new sanctions on Iran's Hormuz income after Trump threatens to hit "hard"

For two days, the world's biggest oil exporter Saudi Arabia has reported drone attacks targeting crude facilities that it blamed on Iraqi armed groups allied with Tehran.

Iran meanwhile launched missiles at US ally Jordan, with Iranian state media later reporting an American attack near the Islamic republic's border with Iraq.

Ahead of the latest strikes, President Donald Trump told Fox News: "We'll be hitting them hard...We are going to beat the f**king s**t out of them."

Iran's state television, meanwhile, reported a US strike in the Piranshahr border area, after the Fars news agency reported a missile hit an uninhabited area, causing no casualties.

Earlier, Jordan's army said it had intercepted five Iranian missiles, with Iran's Revolutionary Guards saying they had targeted US bases there.

"As long as the threats against the Islamic Republic of Iran continue...the resistance will continue," they added.