Its presence is certainly greatest in the resource-rich countries like Nigeria , Angola and Sudan -LRB- where its role has been criticized as contributing to the crisis in Darfur -RRB- .
Sudan
Darfur
/location/country/administrative_divisions
Darfur
Sudan
/location/administrative_division/country
Sudan
Darfur
/location/location/contains
LOCATION
Nigeria
LOCATION
Angola
LOCATION
Sudan
LOCATION
Darfur