EL GENEINA, Sudan, Dec. 10 (UPI) -- Relief workers in Sudan's Darfur region said they were worried a lack of rain could cause water shortages at many of the camps for displaced people.

A recent report warned that 21 camps that are home to some 800,000 people are vulnerable to a severe water shortage in the event of a drought, the U.N. Office for Humanitarian Affairs reported Monday.

A report issued by the NGO Tearfund stated that some locations are already facing a water shortage.

"We've seen examples of tap stands being closed on a particular day and huge queues and struggles, as we see fights breaking out at water points," said John Day, an Oxfam water engineer who works at the Abou Shouk camp.

Another problem, the report showed, is that people in the camps were using more water than they did when living in their villages.

"Darfur characteristically has poor rainy seasons every few years," says hydro geologist Geoff Wright. "But in these circumstances it is going to be very hard to cope with a poor rainy season in the major camps."