Yangon - Relief organisations forced to flee western Myanmar after being targeted by Buddhist mobs say they cannot return unless diplomatic pressure makes the government depoliticise the distribution of aid, otherwise more than 140 000 Rohingya Muslims in overcrowded, dirty camps would be at even greater risk.
In the next two weeks food stocks will run out and at least 20 000 people will be without clean water, according to humanitarian aid workers who gathered with colleagues in the country's main city of Yangon on Monday to discuss the spiralling crisis.
The heath situation is even more dire, they said, with almost no life-saving services such as emergency hospital referrals.
"It's not that we don't want to go back, we can't," said one of the aid workers, who like others at the small, informal meeting asked not to be identified because he was worried about the safety of the local staff who stayed in Rakhine state.
Myanmar, a predominantly Buddhist nation of 60 million people, only recently emerged from a half-century of brutal military rule.
Nascent democratic reforms under a nominally civilian government have generated optimism and brought billions of dollars from international donors - but a violent strain of religious extremism is threatening the progress.
In the past two years, Buddhist mobs torched and pillaged Muslim neighbourhoods, killing up to 280 people and forcing another 140 000 from their homes, most of them Rohingya on the outskirts of Rakhine's state capital, Sittwe.
The Rohingya are described by the UN as one of the most persecuted minorities in the world. International relief groups are almost the sole source of food and medical care in the camps where they are confined.
That has sparked protests by Buddhist extremists, who say aid is being unequally distributed. They have threatened staff, including posting their names, addresses and in some cases photographs, on social networking sites.
As pressure on aid groups mounted, the government in February expelled Doctors without Borders from Rakhine, where it was by far the biggest health care provider, in part because it hired Rohingya.
Then last week, hundreds of Buddhists spent two days attacking the offices and residences of UN agencies, Oxfam, Save the Children, Solidarities International and others in Sittwe, forcing them to evacuate almost all of their staff.
Even if the government ensures protection of aid workers and their premises in the future, it will be difficult to get back to work, said Johannes Kaltenbach, country director of the German medical programme Malteser International, who was not among those present at Monday's meeting.
That's because anyone who works for humanitarian aid organisations is seen as part of the Rohingya lifeline.
"It's hard to find staff," he said. "House owners will be reluctant to rent office space, especially after their property was destroyed. The cars we rent, the people that work for us, all of them are afraid, they feel threatened."
Seeking a short-term solution to the crisis, the United Nations sent a delegation to Sittwe on Tuesday to meet with senior officials from the central and state government.
"We are very, very concerned," said Pierre Peron, the spokesperson for the UN Office for the Co-ordination of Humanitarian Affairs, adding that the world body is trying to work with the government to address some of the most crucial short-term needs in the camps.
They are delivering water to 17 000 people in Pauk Taw, only reachable by boat. They are also helping deliver food from the World Food Programme warehouse, which was damaged in last week's riots but not looted, but there are only rations for around 14 days.
Aid groups urged the US, the European Union and other members of the international community, to also help pressure the central government, saying "we just don't have the teeth".
"The diplomatic community - and the government - needs to understand, unless they can shift this situation, the fate of those in the camps will be on their shoulders."
Even before international aid groups left, the Rohingya were desperate for health care. Respiratory infections and diarrhea - the two biggest child killers worldwide - were already rampant in the sprawling camps that are currently blanketed by choking clouds of dust.
With rainy season approaching, they will soon be overflowing with water and impenetrable mud, sparking fear of cholera or other waterborne outbreaks.
Measles, tuberculosis and other spreadable diseases also remain a worry.
Rakhine, the second poorest state in the country, is home to 1.3 million Rohingya. The government considers them illegal immigrants from neighbouring Bangladesh, though many arrived generations ago.
Denied citizenship by national law, they are not allowed to travel outside of the state. There are also restrictions on the jobs they can hold, how many children they can have, and access to education.
Those living in camps under apartheid-like conditions cannot leave without paying hefty bribes.