About 240,000 children have fled Burma’s Rakhine state into neighbouring Bangladesh over the last three weeks, according to a UN agency.
The figure – amounting to about 60% of an estimated 391,000 Rohingya refugees – includes about 36,000 children under a year old, said Unicef spokeswoman Marixie Mercado.
She added that the children’s agency also estimates about 52,000 pregnant women.
Ms Mercado said the figures include about 1,100 unaccompanied minors who have crossed over the past week.
She spoke at a regular briefing in Geneva that included comments from many UN agencies addressing the crisis in Bangladesh.
Ms Mercado said: “As everybody here is going to tell you, the needs are seemingly endless and the suffering is deepening.”
Chris Lom, Asia-Pacific spokesman for the International Organisation for Migration, said by phone in the briefing that the figures were rough estimates, adding: “There’s not somebody with a clipboard registering them.”
A Rohingya insurgent group attacked police posts in Rakhine on August 25, and the Burmese military responded with “clearance operations”.
Fleeing Rohingya say security forces shot indiscriminately, burned their homes and threatened them with death. The government says hundreds died, mostly Rohingya, and that 176 out of 471 Rohingya villages have been abandoned.
UN secretary-general Antonio Guterres described the violence against Rohingya as “ethnic cleansing”, and A mnesty International said it has evidence of an “orchestrated campaign of systematic burnings” by Burmese security forces targeting dozens of Rohingya villages over the last three weeks.
With refugee camps overflowing and hundreds of thousands of Rohingya struggling to find shelter, food and other essential services, aid workers say they are deeply worried by the continuing influx of people by land and water.
“This is desperate. It’s one of the biggest man-made crises and mass movements of people in the region for decades,” said Martin Faller, a deputy regional director of the International Federation of Red Cross and Red Crescent Societies.
UN refugee agency spokesman Joseph Tripura said that, unless authorities address health concerns, “we might see a very bad situation in coming days” with disease outbreaks.
UN agencies fear continued violence in Burma may eventually drive up to a million Rohingya into Bangladesh.