The number of forest fires in Brazil surged in the first eight months of 2019, official data shows.
Nearly 73,000 fires were recorded between January and August, compared with 39,759 in all of 2018, the embattled National Institute for Space Research (INPE) said.
That is the highest number of forest fires for any year since 2013 and follows two years of declines.
"What we are seeing is a consequence of the increase in deforestation seen in recent figures," said Ricardo Mello of WWF's Amazon Programme.
Brazilian President Jair Bolsonaro on Wednesday accused non-governmental organizations of setting fires in the Amazon rainforest after the government pulled their funding. Mr Bolsonaro said the administration is working to control wildfires.
Forest fires tend to intensify during the dry season, which usually ends in late October or early November, as land is cleared to make way for crops or grazing.
The INPE figures show fires have been concentrated in states occupying the Amazon.
Thick smoke has blanketed several cities in recent days and even caused a commercial flight to be diverted.