An estimated 1,400 children are sole providers for their families in crowded refugee camps along the Bangladesh border, where more than 600,000 Rohingya Muslims have sought sanctuary from violence in Myanmar since August.

Charities fear they are especially vulnerable to illness and emotional stress from shouldering such responsibility, or exploitation as they struggle to provide for their families in the overstretched tent cities.

"This may lead them to child labor and explicit sex work. These families may also experience a spike in child marriages, which is very concerning," said Save the Children International spokesman Rik Goverde, as reported by AFP news agency.

The sight of children carting water jugs, queueing at relief stations or dragging sacks of grain the size of their own bodies is not uncommon in the Rohingya camps.

More than half of the 607,000 new arrivals are children, and aid groups say they are bearing the brunt of Asia's worst refugee crisis in decades.

A full 7.5 percent of the children crammed into one of the camps in Cox's Bazar district are at risk of dying from severe acute malnutrition, the United Nations warned last week.

Meanwhile an estimated 40,000 children have crossed the border completely alone, their parents killed or displaced by violence in Myanmar the United Nations has likened to ethnic cleansing.

To survive such horror only to become sole provider for a family is "something that no child in the world should ever experience," said UNICEF Bangladesh's spokesman Sakil Faizullah.

Schools and safe zones run by aid groups offer some respite from horrific memories and the grim reality of life in the camps, where many children are forced to care for sick or injured parents and traumatized siblings.

The U.N. Security Council unanimously approved a statement Monday strongly condemning the violence that has caused more than 600,000 Rohingya Muslims to flee from Myanmar to Bangladesh, a significant step that still fell short of a stronger resolution that Western nations wanted but China opposed.

The presidential statement calls on Myanmar's government "to ensure no further excessive use of military force in Rakhine State" and take immediate steps to respect human rights, AP reported.

It expresses "grave concern" at reports of human rights violations in Rakhine by Myanmar's security forces against the Rohingya. These include "the systematic use of force and intimidation, killing of men, women and children, sexual violence and ... the destruction and burning of homes and property," it says.

Britain initially circulated a Security Council resolution with similar language, backed by the U.S., France and other council members. But resolutions are legally binding and diplomats said China, a neighbor and ally of Myanmar, was strongly opposed. China is one of the five countries that have veto power on the council.