Egyptians this week have watched the Nile's water turn a murky brown-yellow color, the result of days of heavy rain in parts of the country and subsequent flooding that eroded the surface of lime hills and mountains and swept them into the waterway.

Officials say the murky water, now loaded with silt, has forced the closure of several main water stations. That has caused the disruption of water supplies in some areas.

Egypt, a mostly desert country of some 92 million, is almost entirely dependent on the Nile for agriculture and drinking water.

Experts warned against drinking tap water. Ahmed el-Shennawi, a water expert, told the Rotana Egypt TV network that "change of the color to yellow is a disaster and we should be cautious until water filtering takes place."