The UN refugee agency called on Monday for the immediate rescue of a group of Rohingya refugees adrift in their boat in the Andaman Sea without food or water, many of them ill and suffering from extreme dehydration.

The UN High Commissioner for Refugees (UNHCR) said it did not know the exact location of the vessel and understood that some passengers had died. The boat had left southern Bangladesh about 10 days ago. “Immediate action is needed to save lives and prevent further tragedy,” the UNHCR said.