Updated

Yemeni officials say heavy fighting between pro-government forces and Shiite rebels has killed more than 600 people on both sides in recent days.

Government forces, backed by a Saudi-led coalition, have been advancing along the western coast in recent weeks as they battle the rebels, known as Houthis.

The officials said Monday the fighting has escalated as government forces close in on the Red Sea port of Hodeidah, a vital lifeline through which most of the Yemeni population's food and medicine enters. The officials spoke on condition of anonymity because they were not authorized to brief media.

The coalition has been battling the Iran-allied rebels since March 2015, in a war that has killed more than 10,000 people.