The wildfires are so intense that smoke loomed over the city of Sao Paolo, more than a thousand miles away, according to Greenpeace.
The severity of the fires has prompted the state of Amazonas to declare a state of emergency. The hashtags #PrayforAmazonas and #AmazonRainforest were trending on Twitter on Wednesday.
On Wednesday, Bolsonaro suggested that non-governmental organizations whose budgets have been cut could be responsible for setting fires to make him look bad, alleging that these groups wanted "to draw attention against me, against the government of Brazil." He didn't cite any evidence, according to the AP.
Earlier this month, Bolsonaro fired physicist Ricardo Galvao, director of the INPE.
Wildfires are common during Brazil's dry season but are also deliberately started for the illegal deforestation of land for cattle ranching, the BBC reported.
Scientists warn that if the Amazon fires reach a "point of no return," the forests could be replaced by fire-prone brush and savanna, causing the death of millions of species, according to the World Wildlife Fund.