Updated

The United Nations is warning that a military attack or siege by Yemeni pro-government forces supported by a U.S.-backed, Saudi-led coalition on the port city of Hodeida will impact hundreds of thousands of innocent civilians.

The UN Human Coordinator for Yemen Lise Grande says Friday humanitarian agencies in Yemen "fear, in a prolonged worst case, that as many as 250,000 people may lose everything— even their lives" in and around Hodeida.

The UN and its partners estimate that as many as 600,000 civilians are currently living in and around Hodeida.

Government forces have been trying to seize Hodeida, a vital lifeline from which most of Yemen's population gets food and medicine.

Yemen's civil war has raged since March 2015 between Houthi rebels and government forces backed by the Saudi-led coalition.