A drought in the Amazon has been blamed for the death of six children, who succumbed to illnesses related to the lack of drinkable water, local media reported Sunday, The Associated Press reported. Brazil's National Health Foundation said the victims _ including five indigenous children _ died earlier this week, the Folha de S. Paulo newspaper said on its Web site. Officials said Indian tribes in the western Amazon were the most severely affected by the drought, which has crippled some Amazon River tributaries in recent months. Nearly 84,000 thousand Indians reportedly live in the hard-hit jungle state of Amazonas. The water level in the main trunk of the Amazon River began rising last week, but on Sunday it remained nearly 1.7 meters (5.5 feet) below its average water depth of 17 meters (55 feet), according to the region's port authority. Below average rainfall since January had dropped the river's level by nearly two 2 meters (6 feet) earlier this month. Most of the water course was still navigable but some key tributaries nearly dried out, disrupting travel and damaging the vital fishing industry. River beds are filled with dead fish and rotting river grass, making the water undrinkable. The Health Foundation said earlier in the week it was making available 2 million reals (US$885,000, ¤740,000) in emergency funds to treat water in the most devastated areas. Some of those affected by the drought were excused from voting in Sunday's nationwide referendum on whether to prohibit gun sales because they were unable to reach polling stations.