Authorities had reported that two gas ships were damaged by Wednesday’s blaze, which private security monitor UK-based Ambrey said started with a drone attack on a US-owned-and-operated LNG floating storage vessel.

While energy facilities elsewhere in the region have been hit by drones and missiles over the course of the United States and Israel’s war on Iran, Egypt had so far been spared.

The cabinet said that a preliminary investigation into the incident determined “it resulted from a drone”, noting no one had claimed responsibility.

It added that the inquiry was ongoing “to determine the circumstances of the incident and to take the necessary measures to preserve Egypt’s interests and national security”.

The port authority said in a statement that operations were ongoing as normal despite the attack.

Keplr identified the damaged ships as the Energos Winter storage and regasification vessel and the GasLog Salem tanker, saying they had been moved offshore after the incident.

A private security monitor, UK-based Ambrey, reported that the US-owned-and-operated floating storage vessel was hit by at least one unidentified drone, with a second ship catching fire “in connection with the incident”.

The former head of the Damietta Port Authority, Major General Ayman Salah, told AFP on Wednesday that the regasification ship was moored next to the LNG tanker in the harbour.

“The regasification process takes place under very high pressure,” he said, explaining that any leak could lead to a fire.

Wednesday’s attack took place as the United States and Iran returned to hostilities following a brief lull in fighting aimed at reviving negotiations.

Iran fired a salvo of missiles at US assets in Jordan, while Washington retaliated with a “heavy wave of strikes” on the Islamic Republic.

Houthis not behind drone strike     

Yemen’s Houthi rebels declared on Thursday that they were not behind a drone strike the day before that hit a US-owned-and-operated gas storage ship in the Egyptian port of Damietta.

According to the Houthi-affiliated news agency Saba, an official in the movement’s foreign affairs office said “rumours claiming Yemen targeted a ship in Damietta Port in the Arab Republic of Egypt are unfounded”.