By Associated Press and Shahrzad Elghanayan

Refugee camps in Cox's Bazar, Bangladesh, are overflowing with more than 620,000 Rohingya Muslims who have fled what the United Nations says is a campaign of ethnic cleansing by military in neighboring Myanmar.

An estimated 40,000 unaccompanied Rohingya children are living in Bangladesh.

Photos: Desperate Rohingya refugees face squalor at crowded Bangladeshi camp

Rohingya refugees wait at a relief center at the Balukhali refugee camp at Cox's Bazar. Ed Jones / AFP - Getty Images

Here are some of the organizations helping refugee children: