Hodeidah is the lifeline for most of Yemen's population, who live in Houthi territory. "Some civilians are entrapped, others forced from their homes", said Jolien Veldwijk, the acting country director of the aid group CARE International, which works in Hudaida.
In the meantime, the United Nations Security Council will urgently meet on Thursday, reportedly following a request from the United Kingdom, which, alongside the U.S., is quite ironically one of Saudi Arabia's top arms suppliers and has repeatedly been accused of hypocritically profiteering from the conflict in Yemen.
The officials and residents spoke on condition of anonymity because they were not authorized to brief the media and for fear of reprisals.
Gunfire has erupted near Yemen's port city of Hodeida as a Saudi-led coalition's deadline expired for Shiite rebels there to withdraw.
In a statement made to Emirates News Agency (WAM), Colonel Sadiq Al Duwaid, Spokesman of the Yemeni National Resistance, said the joint resistance forces made a huge advance towards the city of Al Hodeidah, closing in 8 kilomteres within the city's airport and controlling the districts of Al Nekhailah and Al Taif, south of Hodeidah, amid major collapse in the Houthi militias ranks.
"The liberation of the port is the start of the fall of the Houthi militia and will secure marine shipping in the Bab al-Mandab strait and cut off the hands of Iran, which has long drowned Yemen in weapons that shed precious Yemeni blood", the exiled government said in a statement carried by state-run Yemeni media. Houthi forces have fired such missiles at ships previously.
The coalition's initial assault on Hodeidah, which the United Nations has warned could end up killing 250,000 civilians and exacerbate the already awful humanitarian condition, included several airstrikes and also led to the capture of 140 Houthi fighters, UPI reported.
Civil war has raged in Yemen since late 2014, when the Houthis and allied forces seized north-western parts of the country, including the capital Sanaa, and eventually forced President Abdrabbuh Mansour Hadi to flee overseas. Yemen is heavily dependent on imported food, fuel and medicine that come through Hodeidah port.
The United Nations says 8.4 million Yemenis are on the verge of starvation, and for most the port is the only route for food supplies.
Yemen's government declared Tuesday night that negotiations had failed to force the rebels from Hodeida, and that a grace period for UN-led peace efforts was over.
The UN on Monday withdrew all of its global staff from Hodeida ahead of the impending assault, warning that any offensive would put millions of lives at risk. Robert Mardini, regional head for the International Committee of the Red Cross (ICRC), said the attack was "likely to exacerbate an already catastrophic humanitarian situation".
"We call on them to exercise restraint & engage with political efforts to spare Hodeida a military confrontation", he tweeted.
Over 10,000 people have been killed in Yemen's civil war, which has displaced two million more and helped spawn a cholera epidemic.
The United Nations said Friday the worst-case scenario is 250,000 civilians killed in the assault. Following the collapse of their defences, the Houthi fighters abandoned their positions, while their commanders fled the areas after the defeat.
We will update this article when more information becomes available.
The UN special envoy to Yemen, Martin Griffiths, said the world body was talking to both sides to try to avert a battle. A Saudi-led coalition entered the conflict in March 2015. The U.S. has been offering targeting information to the Saudi-led coalition, as well as refuelling their warplanes, though its role in Wednesday's assault wasn't immediately clear.