A spiritual healer from the Nuba Mountains tribe performs during a celebration of their cultural heritage, as part of ongoing events to commemorate the International Day of the World's Indigenous Peoples, in Omdurman August 15, 2015. The International Day of the World's Indigenous Peoples is observed on August 9 annually. (Photo by Mohamed Nureldin Abdallah/Reuters)

Members of Nuba tribe perform during a celebration of their cultural heritage on the International Day of the World's Indigenous Peoples in Omdurman August 15, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

A wrestler of Nuba tribe performs during a celebration of their cultural heritage on the International Day of the World's Indigenous Peoples in Omdurman August 15, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

A wrestler from the Nuba Mountains tribe is seen during a celebration of their cultural heritage, as part of ongoing events to commemorate the International Day of the World's Indigenous Peoples, in Omdurman August 15, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

Performers of Nuba tribe get ready before a celebration of their cultural heritage on the International Day of the World's Indigenous Peoples in Omdurman August 15, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

A performer of Nuba tribe gets ready before a celebration of their cultural heritage on the International Day of the World's Indigenous Peoples in Omdurman August 15, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

A performer of Nuba tribe gets ready before a celebration of their cultural heritage on the International Day of the World's Indigenous Peoples in Omdurman August 15, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

A wrestler of Nuba tribe performs during a celebration of their cultural heritage on the International Day of the World's Indigenous Peoples in Omdurman August 15, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

A spiritual healer of Nuba tribe performs during a celebration of their cultural heritage on the International Day of the World's Indigenous Peoples in Omdurman August 15, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

A wrestler from the Nuba Mountains tribe performs during a celebration of their cultural heritage, as part of ongoing events to commemorate the International Day of the World's Indigenous Peoples, in Omdurman August 15, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

A wrestler from the Nuba Mountains tribe is seen during a celebration of their cultural heritage, as part of ongoing events to commemorate the International Day of the World's Indigenous Peoples, in Omdurman August 15, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

Traditional dancers from the Nuba Mountains tribe perform during a celebration of their cultural heritage, as part of ongoing events to commemorate the International Day of the World's Indigenous Peoples, in Omdurman August 15, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

Traditional dancers from the Nuba Mountains tribe perform during a celebration of their cultural heritage, as part of ongoing events to commemorate the International Day of the World's Indigenous Peoples, in Omdurman August 15, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

A traditional performer from the Nuba Mountains tribe gets ready before a celebration of their cultural heritage, as part of ongoing events to commemorate the International Day of the World's Indigenous Peoples, in Omdurman August 15, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

A traditional performer from the Nuba Mountains tribe gets ready before a celebration of their cultural heritage, as part of ongoing events to commemorate the International Day of the World's Indigenous Peoples, in Omdurman August 15, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

A wrestler from the Nuba Mountains tribe participates in a celebration of their cultural heritage, as part of ongoing events to commemorate the International Day of the World's Indigenous Peoples, in Omdurman August 15, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

A spiritual healer from the Nuba Mountains tribe performs during a celebration of their cultural heritage, as part of ongoing events to commemorate the International Day of the World's Indigenous Peoples, in Omdurman August 15, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

A spiritual healer from the Nuba Mountains tribe performs during a celebration of their cultural heritage, as part of ongoing events to commemorate the International Day of the World's Indigenous Peoples, in Omdurman August 15, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)