At least 85,000 children from the Muslim Rohingya minority are dying of hunger in the western part of Myanmar, the World Food Programme has claimed.
The reports was published after the UN agency conducted interviews across villages in Rakhine state, largely inhabited by Rohingya.
Earlier this year, thousands of Rohingya Muslims fled due to crackdown by Burmese authorities. The crackdown followed a series of coordinated and deadly attacks on police border posts, which the government had blamed on sympathisers of the religious minority.
Those who remained are now facing a food crisis exacerbated by restrictions on freedom of movement and limited access to essential services.
Households most affected by food shortages are in the Maungdaw district, which the report said is among the most vulnerable and chronically food-insecure areas of the country.
WFP estimated that Maungdaw is home to about 880,000 people, of whom 158,500 are children under the age of five. At least 38,000 households, or 225,800 people, are suffering from hunger in the district.
"It is estimated that 80,500 children under the age of five are expected to be in need of treatment for acute malnutrition over the next twelve months,"WFP said.
"The survey has confirmed a worsening of the food security situation in already highly vulnerable areas following the security incidents and ensuing violence in late 2016."
Persecution of Rohingya Muslims
The 1.3 million Rohingya in Myanmar (also known as Burma) are regarded as stateless people and unwelcome migrants from Bangladesh. They live in segregated conditions in Rakhine state. They have been dubbed one of the world's most persecuted ethnic minorities.
The rights group accused government forces of raiding Rohingya villages and carrying out extrajudicial killings, and called for a UN-assisted investigation.
Myanmar's new administration, led by Nobel Peace Prize-winner Aung San Suu Kyi, dismissed the allegations of violence against the Rohingya and accused international media of misreporting the situation in Rakhine.
In June, Burmese authorities refused entry to UN investigators who wanted to conduct an investigation into allegations of violence, rape and torture against Rohingya Muslims.