UAE-backed Yemeni government forces fought their way into Hodeida airport on Tuesday, pressing an offensive that has seen some of the most intense fighting of a three-year war against Huthi Shiite rebels.
The United Arab Emirates, which has US-trained troops fighting alongside the Yemeni army, said the alliance had entered the airport in Hodeida -- a Red Sea port city that is a key aid hub and the entry point for three-quarters of Yemen's imports.
"With the participation and support of the Emirati armed forces, the joint Yemeni resistance (army) entered Hodeida airport," the UAE state news agency WAM tweeted.
A Yemeni military source confirmed to AFP that troops had entered the rebel base at the disused airport on the southern edge of the city.
The battle for Hodeida has sparked fears of a new escalation of the humanitarian crisis in Yemen, which is already teetering on the brink of famine.
The United Nations has warned that any attack on Hodeida port could cripple shipments of desperately needed aid to the 8.4 million Yemenis facing imminent starvation.
Hodeida's residents are now bracing for what they fear will be devastating street fighting, as tanks and buses carrying uniformed troops roll through the empty streets of the once-bustling city.
One resident, who asked not to be identified for fear of arrest, said civilians had been "banned from using their phones to take pictures and are questioned about their movements if they're seen in the streets".
The rebels have also begun to dig trenches in the streets, he said.
Fierce fighting in the Hodeida area has already driven 5,200 families from their homes as pro-government forces advanced up the Red Sea coast, according to the UN.
The coalition launched a major offensive klast Wednesday, dubbed Operation Golden Victory, to drive the rebels out of Hodeida, now the most intense battlefront in an already brutal war.
The battle has killed at least 164 fighters, most of them rebels, medical and military sources said. No civilian casualties have yet been confirmed.
Since Saudi Arabia, the UAE and their regional allies intervened in Yemen in 2015, there have been multiple rounds of UN-brokered peace talks, but they have all failed to achieve any breakthrough.
UN envoy Martin Griffiths has been holding talks in the rebel-held capital Sanaa since Saturday to seek concessions from Huthi leaders that might avoid all-out fighting in the streets of Hodeida.
Griffiths flew out of Sanaa on Tuesday without making any comment to journalists.
The Yemeni government and its allies have insisted that the Huthis must fully withdraw from the city and turn over the port to UN supervision.
The Gulf Arab states accuse their regional arch rival Iran of smuggling arms to the rebels through the port, a charge Tehran denies.
But the rebels have so far agreed only to share control of the port with the United Nations.
Griffiths told the UN Security Council by video-conference on Monday that he was hopeful a first round of preliminary talks could take place next month, according to two diplomats present at the closed-door session.
But he failed to make a breakthrough.
The conflict in Yemen has killed nearly 10,000 people since 2015, most of them civilians.
The coalition intervened when President Abedrabbo Mansour Hadi fled into exile as the rebels overran much of the country.
Its troops have helped pro-government forces to regain control of the south and much of the Red Sea coast but the rebels still control Sanaa and most of the north.
Around 22 million people are now dependent on aid in what was already the Arab world's poorest country.