Brazil was deploying military aircraft as part of a “war” against wildfires ravaging the southeastern state of Sao Paulo, with authorities warning on Sunday that arsonists were setting blazes, writes France24.

Following a crisis meeting of President Luiz Inacio Lula da Silva’s cabinet, Environment Minister Marina Silva announced a “war against the fire” and said federal police were investigating the “atypical situation” that has caused extensive damage.

“So far we have not detected any fire caused by lightning, which means there are people starting fires”, Lula said in a video that he posted on X after meeting with Silva.

Tarcisio de Freitas, the governor of Sao Paulo, by far the country’s most populous state with some 44 million residents, decreed a state of emergency in 45 municipalities and said two people suspected of starting fires had been arrested.

The president promised federal assistance to the states in fighting the blazes, saying there were already 3,000 firefighters working nationwide. With dense smoke drifting across a wide swath of Brazil - even reaching capital city Brasilia 720 km to the north - several flights have been canceled and travel on some roads has been halted.

The military aircraft being deployed include a KC-390 Embraer, a converted troop transport craft that can drop up to 12,000 liters of water on fire zones. The Embraer was sent to one of the communities most threatened, Ribeirao Preto, a city of 700,000 inhabitants about 300 kilometers from Sao Paulo. But Silva said the plane “was unable to operate because of the amount of smoke”, adding: “That gives you an idea of the problem”.