Forest fires in Indonesia raise global warming concerns hinh anh 1The number of blazes in Indonesia's rainforests has rose sharply. (Photo: AFP)

Hanoi (VNA) - Satellite data on September 12 showed the number of blazes in Indonesia's rainforests has rose sharply, spreading smog across Southeast Asia and adding to concerns about the impact of increasing wildfire outbreaks worldwide on global warming.

Illegal blazes to clear land for agricultural farming have been raging on Sumatra and Borneo islands, forcing Indonesia to deploy water-bombing helicopters and thousands of security forces to tackle them.

It is the latest such outbreak worldwide after huge blazes have torn through the Amazon in South America while bushfires are sweeping across eastern Australia.

Indonesia's forest fires are an annual problem but have been worsened this year by particularly dry weather, and in recent days sent toxic smog floating over Malaysia and triggered a diplomatic row.

According to the Singapore-based ASEAN Specialised Meteorological Centre, the number of "hotspots,” areas of intense heat detected by satellite which indicate a high chance of fire, jumped sharply in Indonesia on September 11.

There were 1,619 hotspots detected on Borneo and Sumatra islands, up from 861 a day earlier, according to a tally from the centre, which monitors forest fires and smog outbreaks.

Little rain in the past fortnight, particularly on Indonesian Borneo, has caused the sharpest increase in hotspots.

In 2015, Indonesia suffered its worst forest fires for almost two decades, which dramatically increased its greenhouse gas emissions./.