Heavy fighting on Yemen's west coast kills hundreds, threatens vital aid supply route

Heavy fighting in Yemen between pro-government forces and Shia rebels has killed more than 600 people on both sides in recent days, security officials said Monday.

Government forces, backed by a Saudi-led coalition, have been advancing along the western coast in recent weeks as they battle the Iran-allied rebels, known as Houthis. The fighting has escalated as government forces close in on the Red Sea port city of Hodeidaa vital lifeline through which most of Yemen's food and medicine enters.

The officials spoke on condition of anonymity because they were not authorized to brief the media. Witnesses, who spoke on condition of anonymity for fear of reprisals, said the fighting has forced dozens of families to leave their homes.

A military attack or siege on the Houthi-held western city, long a target in the war, could cost up to 250,000 lives, a senior UN humanitarian official has warned.

The United States urged all parties of the conflict to ensure humanitarian access to the Yemeni people, Secretary of State Mike Pompeo said Monday. The U.S., he said, is closely following developments in Hodeidah and urged Emirati leaders to preserve "the free flow of humanitarian aid and life-saving commercial imports."

Yemen has been embroiled in a civil war pitting the coalition against the Iran-backed Houthis since March 2015. The coalition aims to restore the government of self-exiled President Abed Rabbo Mansour Hadi.

The three-year stalemated war has killed more than 10,000 people and displaced more than threemillion. It has damaged Yemen's infrastructure, crippled its health system and pushed the Arab world's poorest country to the brink of famine.

The UNconsiders Yemen to be the world's worst humanitarian crisis, with more than 22.2 million people in need of assistance. Malnutrition, cholera and other diseases have killed or sickened thousands of civilians over the years.

UNSecretary-General Antonio Guterres said Monday that there has been a recent lull in the fighting and that Martin Griffiths, the UNenvoy for Yemen, "is shuttling between Sana'a and also the UAE and Saudi Arabia to hope that there will be a way to avoid the military confrontation in Hodeida."

A broader UNpeace plan calls on theHouthisto give uptheir missiles in return for an end to a coalition bombing campaign and a transitional governance deal, according to adraft document and sources. Previous UNefforts have failed to end the war.

International aid group Doctors Without Borders said Monday the Saudi-led coalition attacked a cholera treatment centre in the northern province of Hajja.

The group, known by its French acronym MSF, has temporarily frozen its activities in the area, "until we guarantee the safety of our staff and patients," said Joo Martins, MSF's head of mission in Yemen tweeted.