BRASILIA (Reuters) - Brazilian police on Tuesday arrested four volunteer firefighters accused of intentionally setting fires in the Amazon rainforest, but civic leaders said the arrests amounted to government harassment of environmental groups.

FILE PHOTO: Brazilian Institute for the Environment and Renewable Natural Resources (IBAMA) fire brigade members attempt to control hot points during a fire at Tenharim Marmelos Indigenous Land, Amazonas state, Brazil, September 15, 2019. Picture taken September 15, 2019. REUTERS/Bruno Kelly/File Photo

The four firefighters operated in Alter do Chao region of the northern Amazonian state of Para, where a rash of blazes struck earlier this year. Police said the arson was aimed at generating donations to the volunteer fire force.

Making the arrests “was an act of aggression,” congressman Airton Faleiro told reporters at a press briefing in Brasilia organized by the environmental caucus.

Faleiro said the government was seeking to blame the fires on nongovernmental organizations rather than on land grabbers, who environmentalists say set blazes to illegally clear virgin land for farming and ranching.

The number of fires in Brazil’s Amazon spiked in August, sparking global outcry that the country was not doing enough to protect the world’s largest tropical rainforest. Right-wing President Jair Bolsonaro at one point suggested NGOs were to blame for setting the fires.

Civil police for Para said in a statement that they arrested the four members of the Alter do Chao Fire Brigade as a preventative measure amid an ongoing investigation into the causes of the fires.

Police said the firemen had “privileged information and images of the fires” that were suspicious.

“They filmed, published and then were called on by the government to help control the same fires that they caused,” Jose Humberto Melo Jr., an officer involved in the raid, said in a written statement.

“They always claimed to be surprised upon arriving at the scene, but there was no other logical possibility.”

Police said the images were used to defraud donors, including one who gave 300,000 reais ($71,489.85) to the group.

The firefighters and their legal representative could not immediately be reached for comment.

Police also raided a nongovernmental organization called the Health and Happiness Project that is closely associated with fire prevention efforts.

“I personally know the firefighters. They were always trustworthy and of good character,” said Caetano Scannavino, coordinator of the Health and Happiness Project. “This is a joke.”

Scannavino said the police carried out the raids on his NGO without a judge’s order or explanation of the allegations. “They took everything,” he said.

Greenpeace condemned the arrests as “an attempt to criminalize social movements and NGOs that work to preserve the Amazon.”