Attacks by the Houthis on ships in area since November have impacted companies and alarmed major powers in an escalation of Israel's more than three-month war with Hamas in Gaza. The group says it is acting in solidarity with Palestinians.
British and American ships had become "legitimate targets" due to the strikes launched by the two countries on Yemen last week, Nasruldeen Amer, a spokesperson for the Houthis, told Al Jazeera.
"The ship doesn't necessarily have to be heading to Israel for us to target it. It is enough for it to be American," Amer said. "The United States is on the verge of losing its maritime security."
The Houthis previously said they would only target Israeli ships or those en route to Israel.
In the latest apparent attack, the U.S Central Command said Houthi forces in Yemen struck the U.S.-owned and operated dry bulk ship Gibraltar Eagle with an anti-ship ballistic missile on Monday, although there were no reports of injuries or significant damage.
The vessel's U.S.-based operator Eagle Bulk Shipping said it was hit by an "unidentified projectile" while sailing 100 miles (160 km) off the Gulf of Aden. The attack caused a fire in a hold of the vessel, which was carrying steel products, but no injuries, and the ship was continuing on its way, it said.
Earlier in the day, British Maritime Security firm Ambrey said a Marshall Islands-flagged, U.S.-owned bulk carrier was reportedly struck by a missile while transiting near Yemen's port of Aden.
The vessel was assessed not to be Israel-affiliated, according to Ambrey, which also assessed the attack to have targeted U.S. interests in response to the recent strikes on Houthi military positions.
The latest attack suggests that despite the U.S. strikes, the Houthis appear undeterred.
Later on Monday an explosion was heard near Yemen's Hodeidah airport, residents reported. Hodeidah is some distance from Aden, however, and it was not immediately clear what had caused the blast.
Container vessels have been pausing or diverting from the Red Sea that leads to the Suez Canal, the fastest freight route from Asia to Europe. Many ships have been forced to take the longer route via the Cape of Good Hope instead.
Ship-tracking data on Monday showed at least 15 tankers altering course in response to the escalating conflict.
LNG TANKERS
QatarEnergy, the world's second-largest exporter of liquefied natural gas, has joined those avoiding the Red Sea, a senior source with direct knowledge of the matter told Reuters.
Qatar's Al Ghariya, Al Huwaila and Al Nuaman LNG tankers loaded at Ras Laffan and were heading to the Suez Canal but stopped in Oman on Jan. 14, LSEG ship-tracking data showed. The Al Rekayyat, which was sailing back to Qatar, stopped in the Red Sea on Jan. 13.
"It is a pause to get security advice, if passing (through the) Red Sea remains unsafe we will go via the Cape," the source told Reuters regarding QatarEnergy.
The Qatari government and QatarEnergy did not immediately respond to requests for comment.
About 12% of world shipping traffic transits the Suez Canal via the Red Sea.
The longer route round Africa's Cape of Good Hope, which various shipping firms have opted for, can add about nine days to the normally 18-day trip from Qatar to northwest Europe.
The Houthis have been at war with a Saudi-led coalition in Yemen for years, but have turned their sights on the sea to show support for Palestinian group Hamas.
On Sunday, the United States said its fighter aircraft had shot down an anti-ship cruise missile fired by the Houthis toward a U.S. destroyer. No injuries or damage were reported, it said on X.
U.S. ally Britain said it had no desire to be involved in Red Sea conflict but was committed to protecting free navigation.
"Let's wait and see what happens," Defence Secretary Grant Shapps told Sky News on Monday regarding potential further strikes on Houthi sites.
China also called for an end to attacks on civilian vessels in the Red Sea that have placed Beijing's commercial interests at risk.
SUPPLIES AFFECTED
With vessels pausing or diverting, some supply lines are being affected.
Carmaker Suzuki on Monday said it was halting production at its Esztergom plant in Hungary until Jan. 21 as the Red Sea attacks had delayed the arrival of Japanese-made engines.
In energy markets, however, the impact was limited. European benchmark gas prices were lower in afternoon trade on Monday, LSEG data showed, while oil prices lost roughly 1% as the conflict's limited impact on crude output prompted profit taking after oil benchmarks gained 2% last week.
