The authorities said that an attack launched by Houthi rebels on a commercial ship in the Gulf of Aden led to the killing of some of its crew members and forced the survivors to abandon the ship on Wednesday, in the first fatal blow in the group’s campaign of attacks against the backdrop of the war waged by Israel against Hamas in the Gaza Strip.

The attack on the Barbados-flagged bulk carrier, True Confidence, escalates the conflict on a crucial sea route linking Asia and the Middle East to Europe, disrupting global shipping.

 The Iranian-backed Houthis have launched attacks since November, and the United States began an air strike campaign in January that has so far not stopped rebel attacks.

Meanwhile, Iran announced on Wednesday that it would confiscate a $50 million shipment of Kuwaiti crude oil to US energy company Chevron Corp on board a tanker it seized nearly a year ago.

 This represents the latest development in a shadow war that has been ongoing for years in the waterways of the Middle East even before the Houthi attacks began.

Officials said that the targeted attack on Wednesday against the True Confidence organization came after it was welcomed on the radio by individuals claiming to be the Yemeni army.

 The Houthis have been calling in ships by radio in the Red Sea and Gulf of Aden since launching their attacks, and analysts suspect the rebels want to seize the ships.

Two other US officials, who also spoke on the condition of anonymity because they did not have permission to speak publicly, acknowledged that the attack caused “the death of two sailors,” without elaborating.

A US warship and the Indian Navy were at the scene trying to assist in the rescue efforts.

The UKMTO admitted on Wednesday night that its crew had abandoned the ship and it was no longer under command.