Thousands of people from more than 30 flooded villages in northwestern Nigeria faced shortages of food and shelter on Wednesday, with fears building of disease outbreaks.

Officials in Sokoto state said more than 130,000 people had been displaced by flooding three weeks ago when a spillway from the Goronyo dam burst from heavy rains, sweeping through the villages.

Dozens of displaced camps have sprung up in the Goronyo district, where most schools have been turned into shelters for displaced communities, Yusuf Muhammad, a teacher in Goronyo, told AFP.

Aid workers from Doctors Without Borders have set up clinics in three camps to help displaced residents.

Doctors there were treating malaria and infections and they were also concerned about cholera outbreaks due to a lack of clean water.

"The displaced camps are spread all over the Goronyo district and have little access to food, water and latrines," Gautam Chatterjee of the French aid organisation told AFP in a camp in a school in Goronyo.

Large areas of the north of Africa's most populous nation have been hit by flooding in recent weeks, displacing scores of people and destroying huge swathes of farmland.

In Jigawa state, in the north-central region, officials say two dams opened last month caused flooding that affected some two million people, with 50,000 families homeless.

Deadly cholera outbreaks have already hit parts of Nigeria's north this rainy season.

Balla in the northwest was one of the villages completely washed away by the flooding, which forced its 2,000 residents to relocate to a nearby area.

Local authorities have converted the only hospital and primary school in the village where they have relocated to into camps to accommodate them.

"No single house is standing," said Bube Attahiru, a 70-year-old elder of the displaced community who is now sheltering under a tree on the hospital grounds.

"All we had was lost, including our farms, livestock, grains, money and anything of value but our lives."

He said the displaced residents eat food donated by residents with enough to share.

"Food is our major problem because we have lost all our crops and have no money to buy food," said Hajara Maigoro, living at a camp at a primary school where 5,000 displaced from Kagara village are sheltered.

However, unlike most displaced camps, the Balla community had access to clean water from a hand pump on the hospital premises, where a line of women and children waited for water.

Villagers were crammed into offices, hospital rooms and classrooms, up to 40 in each, while the men sleep in the open, said Garba Dandare, a 42-year-old displaced father of four.

Dandare, a fisherman, said his wife and four children sleep with over 30 other women and children in a small maternity ward.

Doctors Without Borders has embarked on an extensive public health education programme in the camps on sanitation and personal hygiene to prevent outbreaks.

"When people are displaced and have no proper sanitation facilities ... it is risky because there is the potential of waterborne diseases, especially cholera which spreads rapidly," Chatterjee said.