Yemeni government forces pushed further into the strategic port city of Hodeida seizing its main hospital in heavy fighting on Saturday as their Saudi-led coalition backers put a brave face on an end to US refuelling support.
A loyalist official said mortar rounds were "falling like rain" in the streets as troops weathered rebel-laid mines and snipers to take control of the main hospital in the city of some 600,000 people.
The rebels have put up fierce resistance to the loyalist advance towards the city's vital docks, which are the point of entry for 80 percent of Yemen's commercial imports and nearly all UN-supervised humanitarian aid.
The suspension of US assistance to re-fuel coalition aircraft comes as Washington's backing of the war effort faces increased scrutiny following international outrage over journalist Jamal Khashoggi's murder last month in the Saudi consulate in Istanbul.
US Democrats, buoyed by a string of midterm election victories, have sought to curtail Washington's military support to Saudi Arabia and demanded greater oversight of a conflict dubbed by the UN as the world's worst humanitarian crisis.
The intensified coalition-backed push into Hodeida, which has claimed the lived of 382 combatants this month, comes despite aid agency warnings of a humanitarian catastrophe in the event of a protracted battle for the city.
Some 14 million Yemenis are at risk of famine and many more are dependent on international aid, according to UN agency figures, making it vital that Hodeida's docks remain open and undamaged.
Yemeni officials said pro-government forces had captured the May 22 Hospital.
Amnesty International had accused the Houthis of "deliberate militarisation" of the facility after they posted snipers on its roof.
Backed by Saudi-led air raids, loyalist troops for the first time entered residential neighbourhoods of Hodeida on Thursday, using bulldozers to remove concrete road blocks installed by the rebels.
Fierce battles raged on Saturday in eastern sectors of Hodeida as loyalist forces backed by air strikes and Apache helicopters sought to push deeper into the city.
"The battles here are turning into street fighting," one loyalist official said.
Save the Children field coordinator Mariam Aldogani spoke of intense coalition air strikes on the city.
"In the last 30 minutes there were more than 15 air strikes... This is the worst time for Hodeida children," she said.
In an apparent face-saving move, Saudi Arabia sought to project the decision to end in-flight refuelling as its own, not Washington's.
The Pentagon provided refuelling capabilities for about 20 percent of coalition planes flying sorties over Yemen.
Saudi-controlled media suggested the coalition had the capacity to make up the shortfall.
Saudi-owned Al-Arabiya Al-Hadath television reported that the kingdom has 23 planes for refuelling operations devoted to Yemen operations, while the UAE has six.
But analysts said the US move would limit the coalition's ability to conduct bombing missions.
"This is a significant decision by the US as this was the most important operational support they provided to the coalition making the US air force a party to the conflict," said Andreas Krieg, a professor at the School of Security Studies at King's College in London.
"The coalition has their own refuelling capability in theory, but air-to-air refuelling is a demanding exercise that neither Saudi Arabia nor the UAE can do as efficiently."
The intensified battle for Hodeida comes despite a surprise call by the Pentagon chief James Mattis last month for a ceasefire in Yemen as he urged warring parties to enter negotiations within 30 days.
The United Nations has since pushed that deadline back to the end of the year.
In an op-ed published by The Washington Post on Friday, the head of the rebels' Supreme Revolutionary Committee, Mohammed Ali al-Houthi, said the escalating offensive in Hodeida showed Mattis's ceasefire call was "nothing but empty talk".
"The recent statements are trying to mislead the world... The United States has the clout to bring an end to the conflict -- but it has decided to protect a corrupt ally," Huthi wrote.
The article infuriated Yemeni government officials, who accused the Post of providing a platform to a "war criminal".
The Houthis have controlled Hodeida since 2014 when they overran the capital Sanaa and swept though much of the rest of the country, triggering the Saudi-led intervention the following year.
The rebels have since been driven out of virtually all of the south and much of the Red Sea coast.