President Luiz Inacio Lula da Silva called an emergency meeting of his cabinet as Brazil's worst drought in seven decades has fueled fires in the Amazon rainforest and the Pantanal wetlands, choking major cities including Rio de Janeiro with smoke.

The capital Brasilia was the latest to be hit, battling its worst fire of the year as residents used buckets of water to dampen their threatened homes.

Three separate fires broke out over the weekend in the Brasilia National Park, officials said, razing about 1,200 hectares by Monday as dozens of firefighters with planes and helicopters battled to contain the onslaught.

"The flames began to come with great speed and at a height of about six meters (19 feet), and the community started to mobilize," nurse Simone Costa, 51, told AFP as she inspected fire damage with her husband and daughter near their home in Brasilia.

"We grabbed buckets of water to control the fire so that it did not move even closer," she said.

Authorities warned that things were likely to get worse in ultra-dry conditions after 140 days without rain in Brasilia.

The number of fires in Brazil so far this month (57,312) has already exceeded the total for September 2023 in its entirety, according to satellite data from the INPE research institute.

Several Brazilian dams are at historically low levels, and cities like Rio are affected by water restrictions.

Though fuelled by drought, which experts say is made more likely by climate change, authorities say most of the fires were set illegally.