Greenpeace picture showing smoke billowing from a fire in the Amazon forest in the municipality of Porto Velho, Rondonia State, Brazil, on July 27, 2022.

The number of forest fires in the Brazilian Amazon increased by eight percent last month compared with July 2021, according to official figures released Monday, the latest alarm bell for the world's biggest rainforest.

Satellite monitoring detected 5,373 fires last month, up from 4,977 in July last year, according to the Brazilian space agency, INPE.

However, the number was well short of the worst July on record: 19,364 fires in 2005.

July is typically the start of the Amazon "fire season," when drier weather fuels more fires—mostly set by farmers and speculators clearing land for agriculture, according to experts.

The increase in the Amazon came as major fires raged in California, France and Portugal amid rising temperatures.

This has been a worrying year for fires in the Amazon, a key resource in the race to curb : INPE has detected 12,906 so far, up 13 percent from the same period last year.

"It's only the beginning of the Amazon dry season, when the number of criminal forest fires unfortunately explodes," said Romulo Batista of Greenpeace Brazil.

"In addition to decimating the forest and its biodiversity, those fires and destruction also affect the 's health due to ," he said in a statement.

President Jair Bolsonaro, who comes up for reelection in October, is facing scrutiny for his government's controversial stewardship of Brazil's 60-percent share of the Amazon, where there has been a surge of fires and deforestation on his watch.

Since the far-right agribusiness ally took office in 2019, average annual deforestation in the Brazilian Amazon has increased by 75 percent compared to the previous decade.