Nearly two months after Muslim Rohingya began fleeing a military-led campaign of violence in western Myanmar, thousands of refugees continue to mass on the Bangladesh border, seeking the relative safety of squalid, muddy camps.

An estimated 582,000 Rohingya have fled into Bangladesh since Aug. 25, when the military began a wave of rape, killing and village burning following attacks on security posts by a Rohingya militant group. The United Nations high commissioner for human rights has called the campaign a “textbook example of ethnic cleansing.”

Drone footage released by the United Nations refugee agency Tuesday shows thousands of Rohingya crowded on embankments just inside Bangladesh, where they gathered while waiting to move to camps that have swollen with refugees in recent weeks.