The UN and Red Cross warned fuel shortages are threatening to halt relief operations in Yemen and urged warring sides to spare hospitals, as Saudi-led air strikes entered a sixth week Friday.
The latest strikes and clashes on the ground killed 47 people in second city Aden, where the Red Cross also scrambled to evacuate staff and patients from a hospital when it became a front line.
And after a meeting in Riyadh, Gulf Arab foreign ministers rejected any moves to hold peace talks between Yemeni rivals at a neutral venue, as sought by Saudi Arabia's arch foe Iran.
The conflict escalated in March when a Saudi-led coalition launched strikes against Iran-backed Shia rebels who overran much of the country, forcing President Abedrabbo Mansur Hadi to flee.
The bombing has virtually halted the delivery of humanitarian aid and other goods, including fuel, with the International Committee of the Red Cross describing the situation as "alarming".
"After a month of air strikes and fighting, Yemen's health system is struggling to cope and there are severe shortages of essential items especially food and fuel," the ICRC said in a statement.
The World Food Programme said it was halting its food distribution due to the shortage of fuel in Yemen where most of the stocks are in the hands of rebels.
"Humanitarian operations will end within days unless fuel supplies are restored," UN chief Ban Ki-moon warned.
Ban called for an "immediate resumption of fuel imports to avoid making the already catastrophic humanitarian situation in Yemen even worse."
The World Health Organization said that as of Monday 1,244 people had been confirmed killed in fighting in Yemen since March 19.
The Red Cross deplored the health care situation in Yemen, where doctors say they are under huge strain to operate hospitals and care for patients with dwindling supplies and almost no fuel.
"The surgical team from the ICRC and all local staff and patients were forced to evacuate Aden's Al-Jumhurriya hospital when the building itself became a front line in the fighting," it said.
The ICRC's mission chief in Yemen said hospitals should be spared.
"We are shocked by the lack of respect for the hospital, as a neutral health facility, by the fighting parties," said Cedric Schweizer.
Doctors in the capital Sanaa, in statements reported by the Red Cross, also spoke of the hardships they are up against.
"We are running out of diesel. Our ambulances can no longer transport patients. Only half of our staff can come to work as the hospital buses have stopped running," said Issa Alzubh, head of Al-Kuwait hospital in Sanaa.
In Aden, Doctor Adel al-Yafyi told AFP his hospital was no longer able to care for ordinary patients because it was being flooded by those wounded in combat or air strikes.
The WHO said the collapse of access to health care had also fanned the spread of epidemic diseases, with 44 alerts of suspected outbreaks of diseases including measles, dengue fever and meningitis.
Last week, Riyadh announced a halt to the coalition air war but it has kept up its strikes every day since.
Saudi King Salman and his son and Defence Minister Prince Mohammed have said repeatedly that it will go on until the rebels concede.
At Thursday's meeting in Riyadh, Gulf foreign ministers insisted UN-brokered peace talks must only take place in the Saudi kingdom.
Iran has proposed the talks be held at a neutral venue where the Houthi Shia rebels could attend.
Saudi Arabia accuses Iran of arming the rebels.
Tehran denies the charges, but a confidential UN report seen by AFP on Thursday gave support to the Saudi allegations.
The report by a panel of experts on the findings of an investigation into the 2013 seizure by Yemeni authorities of an Iranian ship, the Jihan, was presented to the Security Council's Iran sanctions committee last week.
The information collected by the experts "suggests that the Jihan case follows a pattern of arms shipments to Yemen by sea that can be traced back to at least 2009," the report said.
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