The Pentagon says the Sounion is a navigational hazard and warns of a potential environmental catastrophe.

The Greek-flagged Sounion crude oil tanker is still on fire after being attacked by Yemen’s Houthi group last week, and appears to be leaking oil, the Pentagon has said.

The vessel is carrying about one million barrels of crude oil, according to Pentagon spokesperson Air Force Major General Patrick Ryder.

The United States is “aware of a third party that attempted to send two tugs to the vessel to help salvage, but they were warned away by the Houthis and threatened with being attacked,” he told reporters on Tuesday.

The Sounion was attacked on August 21 by multiple projectiles off Yemen’s port city of Hodeidah.

The Iran-aligned Houthis have been targeting shipping in the Red Sea area since November, in what they call an act of solidarity with Palestinians in the Gaza Strip because of Israel’s continuing war on the enclave.

The leaking tanker is both a navigational hazard and a potential environmental catastrophe, Ryder said.

“These are simply reckless acts of terrorism which continue to destabilise global and regional commerce, put the lives of innocent civilian mariners at risk and imperil the vibrant maritime ecosystem in the Red Sea and Gulf of Aden, the Houthis’ own back yard,” Ryder said.

The European Union’s Red Sea naval mission responded to a request from the shipping company and the vessel’s captain and dispatched a unit to provide protection to the crew of 23 Filipinos and two Russians.

The crew abandoned the vessel and were rescued by the EU mission. There were no reports of injuries.

Houthi military spokesman Yahya Saree said the vessel was targeted because its operator, Athens-based Delta Tankers, violated its ban on “entry to the ports of occupied Palestine”.

The Sounion was the third vessel operated by Delta Tankers to be attacked in the Red Sea this month.

It was sailing from Iraq to Greece when it was attacked on August 21, according to Ryder.

The Yemeni group has sunk two ships and killed at least three crew members since it began attacking ships with ties to Israel.

Its actions have affected global shipping, prompting many ship owners to avoid the Red Sea region and send their vessels on lengthier and more costly routes around the southern tip of Africa.