Children make up about 60 percent of the more than 430,000 people who have poured in to Bangladesh over the last four weeks – Rohingya Muslims fleeing terrible persecution in Myanmar. They have seen family members killed and homes set on fire, and they have endured dangerous journeys through forests and on rickety boats. Sometimes they've done it alone. Unicef has so far counted more than 1,400 children who have crossed the border without a parent.

The government of Buddhist-majority Myanmar rejects accusations of ethnic cleansing, saying it is fighting terrorists. But the drawings of some of the children at one of the camps in Bangladesh are filled with traumatic scenes such as people being shot or burned alive by the military.

Twelve-year-old Kurshida drew a helicopter dropping bombs, and the military setting her home on fire and cutting her sleeping niece's throat with a machete.

Rohingya children's drawings
12-year-old Kurshida holds her drawing, which depicts a scene that she witnessed while fleeing her village: the military shooting everywhere, setting her home on fire, cutting her niece's throat with a machete while she slept, her newborn sister being shot, a helicopter dropping bombs, and her neighbours being shot while they tried to flee Allison Joyce/Getty Images

Thirteen-year-old Nurul Haque drew the military setting homes on fire and stomping on the throat of his five-year-old neighbour.

Rohingya children's drawings
13-year-old Nurul Haque holds his drawing which depicts a scene that he witnessed while fleeing his village: the military opening fire on people, setting homes on fire, stomping on the throat of his five-year-old neighbour and shooting people who were walking on the road Allison Joyce/Getty Images

Eleven-year-old Manzur Ali drew several unimaginably horrific incidents that he says occurred while fleeing his village in Myanmar.

"These children have been through a terrible experience. They are heavily traumatised," says Fatema Khyrunnahar, a child protection officer with Unicef who has helped to set up what the agency calls "child friendly spaces" within the squalor and misery of the Rohingya camps. These are rare spaces where these children can be play with each other and have books read to them.

The term "ethnic cleansing" is defined as an effort to rid an area of an unwanted ethnic group – by displacement, deportation or even killing. "When one-third of the Rohingya population had to flee the country, could you find a better word to describe it?" UN Secretary-General Antonio Guterres told a news conference.

UN High Commissioner of Refugees Filippo Grandi said the world has to help the "deeply traumatised" refugees facing enormous hardship. "They had seen villages burned down, families shot or hacked to death, women and girls brutalised," Grandi said. He called for aid to be "rapidly stepped up" and thanked Bangladesh for keeping its border open.