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.

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

A container ship has reportedly caught fire in the Red Sea. The Hong Kong-flagged vessel was said to be drifting in the southern Red Sea roughly 122 nautical miles (226 nm) northwest of Hodeidah, Yemen, during a voyage northbound toward the Suez Canal according to Diaplous Maritime Services.

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.

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.