Some 74,000 Malians, who have been displaced by war and ethnic tensions, are in need of urgent help in the desert of Mauritania, the Doctors without Borders (MSF) aid group said Friday.
In the Mbera camp "humanitarian assistance is insufficient", said the group in a report.
Since January last year, when Tuareg rebels declared the independence of Mali's entire desert north before losing control to armed Islamists, more than 270,000 people have been displaced while 170,000 others fled to neighbouring countries, mainly Burkina Faso, Mauritania and Niger, according to the United Nations.
French forces intervened in Mali in mid-January this year to assist the Malian authorities in retaking the lost territory, and pursue their operations in the north.
MSF said that the displaced at the Mbera camp were also suffering from food insecurity and a lack of basic services, but there was no famine as "rations have improved, food is sufficient now", said MSF emergency official Marie-Christine Ferir. But water is scarce while temperatures soar to 50 degrees Celsius (122 Fahrenheit).
Refugees receive 11 litres of water a day on average but could use 20 for cooking, drinking and personal hygiene.
Children "should get a ration rich in milk and micronutrients so as to avoid malnutrition", Ferir added.
The death rate among children has soared, according to Ferir.
"It is currently above the emergency level," she said, adding that on average two children under the age of two die every day at Mbera, where most refugees are Tuareg, with a large group of Arabs.
"They will not move away any time soon" for fear of reprisals," said Ferir. "That's what they tell us themselves." After an earlier rebellion in the 1990s, "some stayed for several year".
Many Malian villages close to the Mauritanian border have been totally or partially abandoned by their residents after the outbreak of unrest last year.