Nearly a million Rohingya refugees are now in Bangladesh after fleeing violence in neighbouring Myanmar.
Bangladeshi officials have told a United Nations conference the situation was “untenable” and they were trying to work with Myanmar to find a “durable” solution to the world’s fastest growing humanitarian crisis.
The Geneva meeting is trying to raise $434m (£329m) which charities say is needed to provide life-saving aid for the refugees.
Before the meeting got under way, $100m (£76m) was pledged and the EU said it would give an extra 30 million euros (£27m).
International Development Secretary Priti Patel has urged countries to “match words with action and follow the UK’s lead” to fill the “vast gap” in funding.
The UK is the crisis’ biggest donor – it has provided emergency food to 174,000 people, and safe drinking water, emergency toilets and hygiene kits for more than 138,000.
More than 600,000 people from the Muslim minority group have fled Myanmar following attacks by the country’s military and Buddhist mobs in northern Rakhine state since August.
That has brought the total number of Rohingya refugees in Bangladesh to around 900,000.
Refugees say some have been killed and raped and their villages set on fire, with the UN describing their treatment as a “textbook example” of ethnic cleansing.
Shameem Ahsan, Bangladesh’s ambassador to the UN in Geneva, said it was the biggest exodus from a country since the Rwandan genocide in 1994.
He said: “Despite claims to the contrary, violence in Rakhine state has not stopped. Thousands still enter on a daily basis.”
Humanitarian groups have warned there is a lack of aid for those affected, around half of which are children and UNICEF says the crisis shows no sign of abating.
Its executive director Anthony Lake said: “This crisis is stealing their childhoods. We must not let it steal their futures at the same time.”
Mark Lowcock from the UN said the conference was aimed at “mobilising resources to save lives and protect people”.
He added: “This crisis is far from over: The international attention on the Rohingya has perhaps never been greater.”
Our medical teams in Cox’s Bazar have reached 49,000 Rohingya with primary healthcare. More funds are essential to continue this vital work. pic.twitter.com/jO3203jnCV
— Mohammed Abdiker (@AbdikerM) 22 October 2017
There is a serious shortage of water, sanitation and hygiene facilities in the refugee settlements, with an average of 100 people per toilet, according to UNICEF.
UN agencies also told the conference they had managed to give over 700,000 children a vaccine since early October and a bar of soap.
Myanmar’s leader Aung San Suu Kyi said her government was holding talks with Bangladesh about the return of Rohingya.
They would need to prove they were Myanmar residents, but few are thought to have the relevant documents.
Myanmar denies it has carried out ethnic cleansing.