Kutupalong, Cox's Bazar - Massive refugee camps sprawl on open spaces and hillocks in Kutupalong - home to nearly 200,000 Rohingya people, more than half of them arriving in the past one month.

Rohingya men, women, children and older people can be seen milling around, sharing the muddy and narrow streets with 4X4 SUVs carrying aid workers.

In the daily melee, dozens of children go missing.

Nur Nahar has lost contact with her five-year-old daughter Rojina. Sitting at the "lost and found booth", she was crying and thumping her chest, occasionally cursing her luck.

READ MORE: 'Numb and traumatised': Rohingya children recall horror of losing parents

The 29-year-old mother of two rushed to the makeshift booth after hearing a public announcement about missing children being kept there. But until 2pm, there was no trace of her daughter there.

"On Monday [September 18] at around 11am, I took my daughter to the primary health centre at Kutupalong. As I was taking medicines, my daughter went missing," Nur said with tears in her eyes.

"I have searched for her everywhere but could not find her."

Nur's husband, Zahid Hossain, was killed by the military in Shilhati in Myanmar's Razidong district. She fled to Bangladesh with her two children. Her younger son, Rumes, is three years old.

An estimated 480,000 Rohingya have fled Myanmar in the past month after a brutal military crackdown that the UN has called a "textbook case of ethnic cleansing".

"I lost my husband on August 25 and now I have lost my daughter," she told Al Jazeera.

"I could blame the army for the killing of my husband but who do I blame for losing my daughter? It's me who lost a daughter, and bearing this pain is killing me every moment."

Nazir Ahmed has volunteered his services at the Kutupalong missing report centre.

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Since September 5, the 27-year-old has made about 332 missing children announcements, helping nearly 180 children reunite with their families.

Shamsul Alam is one of the lucky parents who found their missing children with the assistance from the booth. He was reunited with his two sons - Sadek Kamal, 8, and Kamal Hossein, 6.

Shamsul and his wife Mahbube Jan lost their children when they went out for breakfast.

They were directed towards the "lost and found booth" run by Nazir, who helped them find their sons.

Moved by the plight of parents and families who had lost their children or other family members, Nazir, himself a Rohingya, decided to start the announcement service.

"I make some 25 to 30 announcements for the missing people each day," he told Al Jazeera.

The UN refugee agency (UNHCR) has since offered a place to establish the makeshift booth and provided a battery and a microphone.

"I have my own daughter and I know what it feels like if you lose your near ones," said Nazir, who works for Handicapped International, an NGO.

Officials at UNICEF and International Committee of the Red Cross (ICRC) say the missing children and the unaccompanied and separated children are the most vulnerable.

Aid agencies fear the children might fall victim to human trafficking.

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The ICRC in cooperation with Bangladesh Red Crescent runs Restoring Family Links (RFL) programme to reunite lost family members while UNICEF has created Children Friendly Spaces (CFS) at the refugee camps.

Three RFL teams are currently operating at Thaingkhali, Balukhali and Kutupalong area, RFL staff Rabby Rahman said.

"We help to reunite the missing children with their families," he said.