DUBAI, United Arab Emirates (AFP) — Maritime security firm Ambrey on Wednesday reported an “explosion” near a Barbados-flagged, United States-owned bulk carrier transiting southwest of the Yemeni port city of Aden.

Ambrey cautioned other ships to steer clear of the bulker which matches the “targeting profile” of Yemen’s Iran-backed Houthi rebels.

The Houthis started harassing ships in the Gulf of Aden and the Red Sea in November, a campaign they say is intended to signal solidarity with Palestinians amid the Gaza war.

They have vowed to strike Israeli, British and American ships as well as vessels heading to Israeli ports, disrupting traffic through the vital trade route off Yemen’s shores.

Before the latest reported attack, Ambrey said the bulk carrier was “hailed by an entity declaring itself to be the ‘Yemeni Navy,’” a title adopted by the Houthi rebels.

British maritime security agency UKMTO also reported an “attack” southwest of Aden, without elaborating.

The attacks have caused several major shipping firms to suspend passage through the Red Sea, which usually carries around 12 percent of global trade.

At least “15 commercial ships have been impacted” since November, including four US ships, US Department of Defense spokesperson Pete Nguyen said on Friday.

The US and Britain have since January launched repeated strikes on Houthi targets in Yemen in response to the ship attacks.