More than two million people have been displaced after authorities had to open flood gates on two rivers, a government official said on Friday.

The flooding began suddenly when the gates on the Challawa and Tiga dams were opened, the spokesman for the Jigawa governor, Umar Kyari said.

About 90 000 hectares of farmland were washed away with food and livestock estimated at 4.5 billion naira destroyed.

The displaced have moved to higher and dry areas where they are sheltering in schools.