More than 1.5 million Nigerians displaced by the militant group Boko Haram are flocking to relief centers across Nigeria's northeast where they find overcrowded facilities and a shortage of supplies.

Almost 10,000 people are in the Damare camp in Adamawa. There are not enough toilets and a persistent health threat looms.

Sylvanus Papka, a top health official, told the Associated Press on Friday that whenever huge numbers of people gather there are bound to be problems like disease that set in.

Papka said outbreaks of diarrhea and measles are now under control thanks to an onsite health clinic.

The influx of displaced people worsens an already fragile situation. Towns that have been hit by the Islamic insurgents can hardly provide secure shelter for residents.