Iran-backed Houthis in Yemen fired six ballistic missiles at two ships in the Red Sea and Gulf of Aden, with one ship reporting minor damage.
A Greek-owned bulked carrier was struck by three of the projectiles fired by the Houthis on Tuesday afternoon.
Earlier in the day, the militants struck a British-owned cargo ship in the Red Sea.
The USS Laboon operating near the Greek ship “intercepted and shot down a third anti-ship ballistic missile fired” by the Houthis, the US Central Command said.
The Greek-owned Star Nasia was damaged by an explosion at 11.15am GMT, a Greek shipping ministry official said.
The fresh attacks come just two days after the US and the UK conducted joint airstrikes targeting Houthi bases in Yemen.
Meanwhile, the US has walked back its previous claims that it informed the Iraqi government it would be conducting airstrikes, saying that information was relayed incorrectly.
Vedant Patel, the state department spokesperson, clarified there “was not a pre-notification” but that they notified the Iraqi government “immediately after the strikes occurred”.
The US conducted retaliatory strikes on more than 85 targets in Iraq and Syria on Friday, resulting in at least 39 casualties.
Following the strikes, the White House refused to rule out US action inside Iran.
On Sunday, president Joe Biden’s national security adviser Jake Sullivan told US news networks that further military action was likely, and would not rule out the possibility of strikes inside Iran’s borders.
“I’m not going to get into what’s on the table and off the table when it comes to the American response,” he told CBS.
Mr Sullivan called the airstrikes “the beginning, not the end of our response”. However, the US has insisted that it does not want a wider conflict across the Middle East.