Since 25 August 2017, an estimated 626,000 Rohingya have crossed into Bangladesh fleeing violence in Myanmar’s Rakhine State, increasing the total Rohingya population in Cox’s Bazar to 839,000. New arrivals are living in spontaneous settlements with increasing need of humanitarian assistance, including shelter, food, clean water, and sanitation. Key challenges include a high risk of communicable diseases due to crowded living conditions and inadequate WASH facilities, limited ability to provide comprehensive protection services due to over-crowdedness with many risks getting exacerbated, and risks such as landslides and floods (the natural flow of water has been severely affected and increased human settlements on the hills and deforestation are aggravating the risks of landslides). IOM is working closely with the Government of Bangladesh (GOB) and the humanitarian community to meet the needs of the displaced population. As displacement continues, the humanitarian and protection needs of the Rohingya also rise. IOM and the humanitarian community are scaling up operations to respond to the needs of new arrivals, existing Rohingya, and affected host communities.