A fire aboard the Hong Kong-flagged ASL Bauhinia on Tuesday was not linked to Houthi attacks, the Red Sea and Gulf of Aden Joint Maritime Information Center said on Wednesday.

The world’s top three container operators said they fear instability in Gaza and broader regional tensions mean continued danger.

British and American ships are tentatively returning to the Red Sea after Yemen’s Houthi rebels vowed to hold off attacks on vessels linked to both nations, a sign that traffic on one of the world’s main trade routes could normalize after more than a year of disruption.

U.S. ships are returning to the Red Sea following promises from Yemen’s Houthi rebels to abstain from attacks on American and British vessels. The pledge, which comes after more than a year of shipping traffic disruption on a major international trade route,

Shipping companies expressed caution about using the shorter route between Asia and Europe that many ships have avoided for more than a year.

Mandeb strait decreased by 50% after the Yemeni rebels launched maritime attacks, according to the US Energy Information Administration.

An explosion forced the crew of a Hong Kong-flagged container ship to abandon the vessel Tuesday near the coast of Yemen, shipping industry officials said.

An official described the cargo aboard the ASL Bauhinia container ship as ‘dangerous’. The cause of the fire was not immediately clear.

An explosion has struck a Hong Kong-flagged container ship traveling north through the Red Sea, sparking a major fire that forced its crew to abandon the vessel