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

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.

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.