Brasilia's iconic futuristic buildings, designed by architect Oscar Niemeyer, have been engulfed in a thick haze of smoke in recent days.

Several parts of Brazil are suffocating due to raging wildfires, but the fumes are new to the modernist capital, whose residents are used to expansive blue skies and clean air during the dry season.

"I have lived in Brasilia for 30 years, this is the first time I have seen this kind of smoke," said Moacir do Nascimento Santo, 47, a driver with two young children.

"(It) compromises our breathing, our vision, and it is worrying for the children -- they suffer with all this smoke," he told AFP.

Situated in the center of the country, Brasilia was carefully planned from scratch on an empty plateau to become the capital in 1960, and is now home to 2.8 million people.

Its wide avenues, organized neighborhoods and green, open spaces are a world apart from other Brazilian cities such as Rio de Janeiro or Sao Paulo -- and much less polluted.

Forest fires have been raging for several weeks in Brazil, particularly in the Amazon rainforest in the north and the immense Pantanal wetland in the center-west of the country.

The smoke engulfing Brasilia is a result of fires near the capital, but also winds bringing in smoke from other regions, particularly the southeastern state of Sao Paulo, several hundred kilometers away, where bushfires devastated thousands of hectares of agricultural land last week.

Authorities say most fires are human-caused.