The death toll from US airstrikes on an oil port in western Yemen has risen to at least 74 people, the Houthi-run health ministry reported, marking the deadliest day since the United States escalated its aerial campaign against the Iran-backed group last month.

Ras Isa is a critical oil pipeline and port, one of three on the country’s west coast through which the vast majority of imports and humanitarian assistance enter Yemen. Central Command argued the Iran-backed Houthi rebels, which America considers a terrorist group, were using the site as a fuel supply facility and for graft.