There are more than 800,000 Rohingya refugees living in Bangladesh. About 480,000 have fled Rakhine since Aug. 25, when Myanmar’s army began an operation against a minority group in retaliation for an attack by an armed Rohingya faction called the Arakan Rohingya Salvation Army.

The operation has emptied dozens of villages and forced people to flee the violence across Myanmar's borders.

Sixty percent of these new refugees are children below the age of 18, according to UNICEF. And many of them like Mohammad — cold, scared, traumatized — are making the journey alone.

As of Sept. 20, UNICEF and other humanitarian organizations have identified as many as 1,400 unaccompanied children who crossed the border alone — without their parents or any other relatives. It’s likely that this number vastly underestimates the real amount, aid workers say.