Porto Velho: Hundreds of new fires flared up in the Amazon. This even as Brazil’s military aircraft dumped water over hard-hit areas

Smoke choked Port Velho city as fires raged in the north-western state of Rondonia where fire-fighting efforts are concentrated, amid a growing global uproar and a diplomatic spat between France and Brazil.

Two C-130 Hercules aircraft carrying thousands of litres of water on Sunday began dousing the blaze as it devoured chunks of the world's largest rainforest, which is seen as crucial to keeping climate change in check.

Experts say increased land clearing during the months-long dry season to make way for crops or grazing has aggravated the problem this year.

Brazil's President Jair Bolsonaro has ordered an investigation into reports that rural producers in the northern state of Para held a "day of fire" on August 10 in a show of support for the far-right leader's efforts to weaken environmental protection monitoring in the region.

G7 nations pledged to help combat the blaze, the countries came together in providing an aid of $22million.

French President Emmanuel Macron, who is hosting the G7 Summit said that $22million has been raised but Brazilian President Jair Bolsonaro has turned the offer down without giving an explanation.

Bolsonaro hit back, accusing Macron of treating Brazil like "a colony or no-man's land."

The G7 club also agreed to support a medium-term reforestation plan which will be unveiled at the UN in September, Macron and Chile's President Sebastian Pinera said. Although about 60% of the Amazon is in Brazil, the vast forest also spreads over parts of eight other countries or territories.

Bolivian President Evo Morales said Sunday he would accept international help to combat wildfires raging in his country's southeast as he suspended his election campaign to deal with the crisis.

The country took delivery, on Friday, of a Boeing 747-400 "supertanker" capable of carrying 150,000 liters (40,000 gallons) of water. Brazil has accepted help from Israel, which offered to send an aircraft.

Seven states, including Rondonia, have requested the Brazilian army's help in the Amazon, where more than 43,000 troops have been made available to combat fires. It is not clear how many of them are actually involved in fire-fighting efforts so far.

After initially blaming the fires on non-government organizations, Bolsonaro on Friday vowed a "zero tolerance" approach to criminal activities in the Amazon and promised strong action to control the blazes.

Bolsonaro's delayed response came as the Amazon crisis threatened to torpedo a massive trade agreement between the European Union and South American countries, including Brazil, which had alarmed the powerful agriculture sector.