The Iran-aligned Houthi movement fought on Saturday to keep a Saudi-led coalition from taking full control of the airport in the port city of Hodeidah, in an offensive the UN says could trigger a famine imperiling millions of lives.
The alliance, led in the Hodeidah assault by the United Arab Emirates, is attempting to capture the airport in the well-defended city and push the Houthis out of their sole Red Sea port, in the biggest battle of the war.
"Death and poverty are all around us. We are scared to leave our homes after the fighting reached the airport," said Abdelqader, a resident who used to work at a cement plant. "No work, no salary, we are just waiting for God's mercy."
Ground troops — which include United Arab Emirates forces, Sudanese and Yemenis from various factions — have surrounded the main airport compound but have not seized it, a source in the coalition-allied Yemeni military and residents said.
"We need some time to make sure there are no gunmen, mines or explosive in the building," the military source said. The military's media office said technical teams were de-mining the surrounding area.
Martin Griffiths, the UN special envoy to Yemen, arrived in the Houthi-held capital Sanaa as fears grew that fighting will severe the only lifeline to the vast majority of Yemenis.
The battle for Hodeidah could have ramifications far beyond the densely-populated city of 600,000. Yemen's conflict is part of a regional proxy war between Saudi Arabia and Iran.
President Donald Trump's withdrawal from the nuclear deal and his embrace of nuclear state North Korea have added to Iran's isolation and put pressure on the Islamic Republic to preserve its interests in Yemen and other Arab states.
Fighting led to the closure of the northern entrance of the western city Hodeidah, which leads to Sanaa, blocking a key exit out of the city and making it harder to transport goods from the country's largest port to mountainous regions.
Aly Omar and his family spent three days trapped in the Manzar neighborhood abutting the airport as fighting raged.
"We didn't have any food, or drink or anything, not even water," Omar said, standing in a hospital on Friday night beside his son, who was wounded by an air strike.
"I treated him on a bus after he was injured in an air strike, which is unacceptable. I call on the United Nations and the Red Cross to open a way for us to get out of the situation we're in. Our kids, women and elderly are stuck ..."
Samy Mansour, head of the emergency room at Al-Thawra Hospital said: "We're still treating people on the scene and transporting them to the hospital."
Around 22 million people in Yemen depend on the humanitarian aid, with 8.4 million at risk of starvation. Aid groups have failed to cope with one of the world's worst humanitarian crises.
"Humanitarian agencies cannot currently access areas south of the city where people are most likely to have been injured, affected and displaced, leaving us without a clear picture of needs," said the Norwegian Refugee Council's office in Yemen.
The Arab alliance, which launched the operation in Hodeidah four days ago, said it can take the city quickly enough to avoid interrupting aid and would focus on capturing the airport and port and avoid street-to-street fighting in the city.
Lise Grande, the United Nations humanitarian coordinator in Yemen, has warned that up to 250,000 lives are at risk, in the worst case scenario.
Riyadh accused the Houthis of using the port to smuggle Iranian-made weapons, including missiles that have targeted Saudi cities - accusations denied by the group and Tehran.
If the Hodeidah fighting drags on, causing big coalition casualties and an outcry over a humanitarian catastrophe, it may work in the Houthis' favor. If the Houthis are driven out, the coalition could get the upper hand in the war.
The alliance has superior weaponry, including fighter planes. The Houthis, highly experienced in mountain warfare, have advanced on sandal-shod feet and by pickup truck in battles across Yemen.
The United States and other Western powers have provided arms and intelligence to the Arab alliance. Human rights groups criticize them over coalition air strikes, which have led to hundreds of civilian deaths.
French special forces are on the ground in Yemen with the UAE forces, the French newspaper Le Figaro reported on Saturday, citing two military sources.
Houthis rule the most populous areas of chronically unstable Yemen, a poor nation of about 30 million people. More than 10,000 people have died in the war.
The Saudi-led alliance intervened in 2015 to restore an internationally recognized Yemeni government in exile and thwart what Riyadh and Abu Dhabi see as efforts by archfoe Iran to dominate the region.
Even if the Houthis are defeated in Hodeidah, securing peace would be an arduous process in a civil war complicated by other parties, including loyalists of the late President Ali Abdullah Saleh, southern separatists and Al Qaeda.