(CNN)The first monsoon rains have hit camps housing hundreds of thousands of Rohingya refugees in Bangladesh, causing the death of one young child, and destroying hundreds of makeshift shelters, as aid agencies warn of a humanitarian catastrophe as the wet season gets underway.
Rohingya 'living on sandcastles' as first monsoon rains hit fragile camps
UN refugee agency UNHCR reported that "large areas of the camp were underwater," following the downpour, which has so far caused 21 landslides, according to agency estimates.
"Rain came down in sheets all last night," said UNHCR spokeswoman Caroline Gluck, adding that landslides will continue as "the land has been stripped of all vegetation, to make way for the building of makeshift homes. People are practically living on sandcastles."
Around 2.30 a.m. Monday morning a mud wall in a shelter in the Kutupalong camp collapsed, killing a 3-year-old boy and injuring his mother, Rezaul Karim, of Bangladesh's Ministry for Disaster Management and Relief and manager-in-charge of the camp, the largest in Bangladesh, told CNN.
As many as 300 family shelters have been damaged, according to Bangladesh's Ministry for Disaster Management and Relief.
The rains will potentially imperil upwards of 200,000 Rohingya refugees huddled in low-lying makeshift camps along the country's eastern border. The monsoon season typically lasts until around October.
More heavy rain is forecast for coming days.
Hundreds of thousands of Rohingya -- an ethnic Muslim minority -- have fled Buddhist-majority Myanmar into neighboring Bangladesh since August 2017, bringing with them stories of murder, rape and the destruction of villages at the hands of the military.
The UN and the United States say they believe the violence against the Rohingya constitutes ethnic cleansing, a charge denied by the Myanmar government.