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.

Supply chains have had to deal with higher shipping costs, product delivery delays, and increased carbon emissions as a result of this diversion. The Gaza ceasefire gave some hope that the disruption would finally end. But shipping lines will not hurry back to the region until long-term security is guaranteed.

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,

Yemen’s Iran-backed Houthi movement has released the crew of a cargo ship more than a year after its fighters hijacked the vessel in the Red Sea, as part of its campaign of attacks in support of Hamas in its war against Israel.

Yemen’s Houthi rebels have signaled they will limit their attacks in the Red Sea corridor to only Israeli-affiliated ships as a ceasefire in the Gaza Strip takes hold.

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. A maritime security source told Reuters that the fire resulted from hazardous cargo on board.

GENEVA (Reuters) - Operations at a Red Sea port in Yemen used for aid imports have fallen to about a quarter of its capacity, a UN official said on Tuesday, adding it was not certain that a Gaza ceasefire would end attacks between the Iran-backed Houthis and Israel.

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

The world’s top three container shippers, MSC Mediterranean Shipping, A.P. Møller-Maersk (OTCPK:AMKBY) (OTCPK:AMKBF) and CMA CGM, have said in recent days they will not send vessels back to the Red Sea despite a pledge by Houthi militants in Yemen not to attack them as long as a ceasefire in Gaza holds.

With the ceasefire between Israel and Hamas in Gaza, Houthi rebels in Yemen have stopped missile attacks on ships in the Red Sea and have also released a shipping crew held hostage for over a year.

Companies transporting their products around the world are not ready to return to the Red Sea trade route in the wake of a Gaza ceasefire deal because of uncertainty over whether Yemen's Houthis will continue to attack shipping,