The International Rescue Committee says more than 60 people have died in recent weeks attempting to leave the last area controlled by the Islamic State group in eastern Syria.
Exhaustion and malnutrition are the main causes of the deaths, said Paul Donohoe, a spokesman for the aid group, on Monday.
At least 62 people died, two thirds of them children under the age of one, he said.
They died either on their way to safety or upon reaching the al-Hol camp, an Internally Displaced Persons (IDP) camp to which more than 30,000 people have flooded in the last few weeks from battles over Syria's last IS-held area.
Almost 42,000 people are now resident in the camp in Hassakah.
The Kurdish-led Syrian Democratic Forces (SDF) continue to fight more than 300 Islamic State militants who are making their last stand in a tiny stretch of land in Baghouz.
The fighters are refusing to surrender and are instead attempting to negotiate an exit to Idlib, where a double bomb attacked killed 16 and wounded more than 70 people on Monday.
Source: The New Arab.