About 60,000 Syrian refugees stuck in the desert on the Jordanian border have received no aid for more than a week, Medecins Sans Frontieres (MSF) says.
The Jordanian authorities declared the border a closed military zone after a bomb attack near the informal camp at Rukban killed seven security personnel.
Since then, no food or medical assistance, and only extremely limited water, have reached the refugees.
MSF warned that the situation at Rukban was getting worse by the hour.
Conditions were already extremely harsh, with 214 of the 1,300 children under five years old screened by MSF teams malnourished and 24.7% of the children they saw suffering from diarrhoea, it said.
Before the attack, Jordan was allowing in only about 50 to 100 refugees from Rukban and another camp at Hadalat each day, citing security concerns.
“These people – more than 50% of whom are children – desperately need the immediate resumption of the provision of food, water and medical care. This cannot wait,” said Benoit De Gryse, MSF’s operations manager.
“But assistance alone is not enough. People fleeing war should be offered international protection and a safe place to relocate. Neither Syria nor the border are safe today,” he added.
On Thursday, a UN World Food Programme spokeswoman expressed concern for the refugees, saying they were “enduring very harsh weather conditions, sweltering heat and frequent dust storms” and had run out, or were running out, of food.
Since the attack, aid groups had only twice been able to deliver water to the camp, she told AFP.
The International Committee of the Red Cross said criminal gangs were taking advantage of the crisis to sell food and water at exorbitant prices.
Mr De Gryse described the situation at Rukban as a “massive failure of the international community”.
“This is not just Jordan’s responsibility. There are plenty of countries both in and outside of the region who should also step up to offer a safe place for refugees,” he said.
Jordan is hosting 655,000 of the 4.84 million Syrians registered as refugees with the UN. Officials say more than one million other Syrians are living there, including those who arrived before the uprising against Mr Assad began in 2011.
Situazione in Libano: l’intervista a Giuseppe Cammarata
“Improvvisamente il palazzo ha tremato, sembrava un terremoto. Abbiamo sentito un boato spaventoso: con le altre persone che sono con me ci siamo riparati in un luogo sicuro, poi siamo scesi in strada e abbiamo capito quello che era successo”. E’ la testimonianza all’AdnKronos di Giuseppe Cammarata, rappresentante in Libano di Arcs Culture Solidali.