The United Nations has appealed for massive help for nearly 400,000 Muslims from Myanmar who have fled to Bangladesh.

Concern growing that the number could keep rising, unless Myanmar ends what critics denounce as “Ethnic Cleansing”.

The Rohingya are fleeing from a Myanmar military offensive in the Western State of Rakhine that was triggered by a series of guerrilla attacks on Aug. 25 on security posts and an army camp in which about a dozen people were killed.

The United Nations has called for a massive intensification of relief operations to help the refugees, and a much bigger response from the international community.

The violence in Rakhine and the exodus of refugees is the most pressing problem Nobel peace laureate Aung San Suu Kyi has faced since becoming national leader last year.

U.N. Secretary-General Antonio Guterres and the U.N. Security Council on Wednesday urged Myanmar to end the violence, which he said was best described as ethnic cleansing.

The government of Buddhist-majority Myanmar rejects such accusations, saying it is targeting “Terrorists”.