Yemen's Houthi rebels have resumed their attacks on Red Sea shipping, saying they aim to force Israel to cease fire in Gaza -- a move that threatens a truce with Washington and rattles maritime trade.

Commercial ships are broadcasting messages about their nationality and even religion on their public tracking systems to avoid being targeted by Yemen's Houthis.

A ship came under attack Sunday in the Red Sea off the coast of Yemen by armed men firing guns and launching rocket-propelled grenades, a group overseen by the British military said. No one immediately claimed responsibility for the attack.