Iran vowed on Thursday to keep striking the region so long as it remains under attack, AFP reported on Thursday.
The war resumed following a ceasefire that lasted just a few weeks, throwing the region and global energy markets back into chaos as Iran and the United States battle for control of the vital Strait of Hormuz.
The Houthis this week joined the conflict, claiming to have struck two oil tankers.
Meanwhile, Jordan and Kuwait both reported intercepting strikes as Iran's military and Revolutionary Guards claimed to be targeting US assets in both countries.
"The armed forces' retaliatory attacks will continue as long as the US attacks on the country's infrastructure and coastal areas continue," Iran's army spokesperson Mohammad Akraminia said, according to state TV.
- 'Eye for an eye' -
The developments followed fresh US strikes on Iranian military targets, with US Central Command reporting its twelfth consecutive night of strikes, saying it aimed to "further degrade Iran's ability to threaten civilian mariners and commercial vessels transiting regional waters".
President Donald Trump on Wednesday said the US would bomb Iranian civilian infrastructure every time Tehran fires at ships in Hormuz.
"Any time the Islamic Republic of Iran shoots at a ship in the Strait of Hormuz, whether it be by Missile, Rocket, Drone, or any other device or weapon, the United States will bomb and destroy ONE BRIDGE OR POWER PLANT," Trump wrote on social media.
Iranian Foreign Minister Abbas Araghchi said Tehran would respond in kind to any attack on its infrastructure, writing: "Our defense doctrine is clear: eye for an eye."
Iranian state media said Thursday that a US attack killed two people at Shalamcheh on Iran’s border with Iraq.
It also reported two US missiles hit Bushehr, home to the country's only civilian nuclear plant and a frequent target of Washington's strikes.
- Houthis step in -
The Houthis said they had carried out missile and drone strikes on two tankers in the Red Sea.
British naval security monitor UKMTO said the master of a tanker reported being hit by an unknown projectile about 70 nautical miles southwest of Al Shuqaiq, causing a fire that the crew was fighting.
In Hormuz, the Revolutionary Guards said they stopped three oil tankers from transiting, as the US and Iran vie for control over the route through which around one fifth of the world's oil passed before the war.
"The Strait of Hormuz is under our control... and any ship that is deceived by the US and intends to pass without coordination with the Islamic Republic of Iran will suffer the same fate," the Revolutionary Guards said.
Oil prices again climbed Thursday, with Brent crude, the global oil benchmark, up four percent at $97.80 a barrel and bringing back fears of spiraling consumer prices and slowed growth globally.
On the sidelines of a Southeast Asian summit in Manila, US Secretary of State Marco Rubio said the Houthis had been "suckered" into attacking Red Sea shipping by Iran.
"The Houthis largely were smart and stayed out of all this throughout the conflict, but they now apparently have gotten themselves suckered into this, going after Saudi Arabia and their ships," Rubio said.
"I hope they will de-escalate, because I think the Houthis, frankly, got snookered into this thing by the Iranians."
