GENEVA — Nearly 200 people who fled Boko Haram attacks have died of malnutrition and sickness in a single camp in northeastern Nigeria in the past month, the medical charity Doctors Without Borders said on Thursday, describing a “catastrophic humanitarian emergency.”

In the camp, which sits on the outskirts of the largely ruined Nigerian city of Bama, the charity said that the local authorities reported five to six people dying every day.

“We have been told that people, including children there, have starved to death,” Ghada Hatim, the group’s head of mission in Nigeria, said in a statement.

Years of devastating attacks by Boko Haram have displaced more than two million people in Nigeria and surrounding countries. The Nigerian city of Maiduguri has more than doubled in size as people flee villages for the town, which is now swarming with soldiers and local vigilantes bent on keeping out Boko Haram.