A bushfire in northern Thailand has destroyed vast swathes of forest and sent air pollution soaring to 20 times the safe level.

The blaze started in the Doi Suthep-Pui National Park in Chiang Mai, northern Thailand, on Wednesday morning (March 24) with fire crews working through the night to finally bring it under control the next morning. 

Footage shows how thick clouds of smoke from the fire covered the forest area and also the town. More than 500 local fire crews and rescue workers battled the blaze with assistance from soldiers from the 3rd Army Region.

The country's Prime Minister Prayut Chan-o-cha expressed concerns over the blaze. While Chiang Mai governor Charoenrit Sanguansat said the fire had caused ''extensive damage''.

Charoenrit said the bushfire sent PM2.5 levels in the city to "record levels" of around 1,000 microgrammes per cubic metre, 20 times above levels considered safe by the country's Pollution Control Department (PCD).

Environment boss Komsan Suwanampa is now worrying about the long term effects of the blaze, which is believed to have started because of dry conditions and heat.

He said: "We are trying our best to control the fire but I'm concerned that if the situation keeps worsening it could cause a negative effect on the health of the locals in the long run."

A bushfire in northern Thailand has destroyed vast swathes of forest and sent air pollution soaring to 20 times the safe level.

The blaze started in the Doi Suthep-Pui National Park in Chiang Mai, northern Thailand, on Wednesday morning (March 24) with fire crews working through the night to finally bring it under control the next morning. 

Footage shows how thick clouds of smoke from the fire covered the forest area and also the town. More than 500 local fire crews and rescue workers battled the blaze with assistance from soldiers from the 3rd Army Region.

The country's Prime Minister Prayut Chan-o-cha expressed concerns over the blaze. While Chiang Mai governor Charoenrit Sanguansat said the fire had caused ''extensive damage''.

Charoenrit said the bushfire sent PM2.5 levels in the city to "record levels" of around 1,000 microgrammes per cubic metre, 20 times above levels considered safe by the country's Pollution Control Department (PCD).

Environment boss Komsan Suwanampa is now worrying about the long term effects of the blaze, which is believed to have started because of dry conditions and heat.

He said: "We are trying our best to control the fire but I'm concerned that if the situation keeps worsening it could cause a negative effect on the health of the locals in the long run."

ENDS