The US military reports that three commercial vessels have been attacked four times in international waters in the southern Red Sea. It says missiles were fired from areas controlled by Houthi insurgents in Yemen. No casualties have been reported.

The US Central Command reported in a statement on Sunday that a US destroyer conducting a patrol in the waters responded to the distress calls from the ships, shooting down drones in some of the incidents.

The statement said the USS Carney detected an anti-ship ballistic missile attack toward a Bahamas-flagged cargo ship owned and operated by a British firm around 9:15 a.m. on Sunday. It said the missile was fired from Houthi-controlled areas of Yemen, and fell in the ship's vicinity.

The central command said that about three hours later, the same cargo ship reported that it had been struck by a missile fired from Houthi-controlled areas.

It said the Carney responded to the distress call and was assisting with the damage assessment, when it detected an inbound drone and shot it down.

The central command said a Panamanian-flagged bulk carrier owned and operated by a different British firm was struck by a missile from Houthi-controlled areas around 3:30 p.m. The ship reported damage.

It said that about an hour later, another Panamanian-flagged bulk carrier, crewed by sailors from eight countries, sent a distress call stating that it had been struck by a missile. No significant damage was reported. The Carney shot down a drone while en route to render support.

The US central command said there were no casualties in any of the attacks.

In the statement, it said the attacks "represent a direct threat to international commerce and maritime security."

The US military went on to criticize Iran, which supports the Houthis. It said, "We also have every reason to believe that these attacks, while launched by the Houthis in Yemen, are fully enabled by Iran."