Maritime security firm Ambrey on Wednesday reported an "explosion" near a Barbados-flagged, US-owned bulk carrier transitting southwest of the Yemeni port city of Aden.

"A nearby vessel reported an explosion in the proximity of the Barbados-flagged, publicly US-owned, bulk carrier," Ambrey said, cautioning other ships to steer clear of the bulker which matches the "targeting profile" of Yemen's Iran-backed Huthi rebels.