Up to 1,000 people displaced by floodwater from a collapsed damn in Nigeria’s northwestern Zamfara state huddled together on Tuesday waiting for word of dozens of their missing relatives.

“I haven't been able to find my wife and three children,” said Sule Abubakar, whose home vanished along with more than 500 others when the Barrage Dam outside the state capital, Gusau, collapsed on Saturday.

Red Cross officials providing assistance to 700 people seeking shelter at the Birnin Ruwa secondary school said the displaced needed urgent food and medical assistance.

At Birnin Ruwa, village leader Muhammadu Ruwa said more than half of the 98 people missing immediately after the flood have been found in different shelters. He said he hoped those still missing might be found.

Apart from destroying homes, the water also washed away many acres of farmland and some people have lost their entire season’s crop. Wells on which people depend for drinking water have also been polluted by the floodwaters.

Sluice gates used to let water out of the reservoir failed to function, causing the rain to overwhelm the dam, said an official of the Zamfara Water Board, which operates the dam that supplies water to Gusau.

Zamfara is part of Nigeria’s relatively arid Sahel belt, which faces torrential rains between August and October, often leading to large-scale flooding. In recent days, flooding in the Shagari local government council of Sokoto state, north of Zamfara, also displaced hundreds of people and washed away farmlands.