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.

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.

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.

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.