Shocking levels of pollution engulfed northern Thailand where farmers defied orders and continued burning crops.

A toxic blanket of smog which had strangled capital Bangkok for since the middle of January slowly dispersed after winds arrived but it is expected to return on Wednesday.

While in the northern provinces, smoke carpeted the sky over the weekend caused by farmers setting fire to sugar cane and maize husks from their plantations after harvesting.

Footage from Phrae, neighbouring the Chiang Mai province popular with backpackers in the north, shows hazy skies with the levels of PM 2.5 particles soaring to 200 per cubic metre of air - quadruple the safe levels of 50.

Phrae Governor Pongrat Piromrat said: ''We are working hard to reduce the air pollution but I am still not satisfied. Firefighters will be sent to any locations where farmers are making fires and they will extinguish the flames.''

Governor Somsak Changtragul from Khon Kaen, another badly affected region, said: ''We have asked factories to blacklist farmers who bring in sugarcane that shows burn marks, a sign that the farmer set fire to his field at a time when the air pollution is serious.''

Pollution Control Department chief Phuwiang Prakammin said air quality around Bangkok had improved because breezy weather had blown away fine dust particles and smoke.

However, the Meteorological Department warned Bangkok's levels of pollution will increase between February 13 and 15.

Shocking levels of pollution engulfed northern Thailand where farmers defied orders and continued burning crops.

A toxic blanket of smog which had strangled capital Bangkok for since the middle of January slowly dispersed after winds arrived - but is expected to return on Wednesday.

While in the northern provinces, smoke carpeted the sky over the weekend and this morning. It was caused by farmers refusing to spend money to remove sugar cane and maize husks from their plantations after harvesting is complete and instead setting fire to the vast swathes of land to clear them.

Footage from Phrae, neighbouring the Chiang Mai province popular with backpackers in the north, shows hazy skies with the levels of PM 2.5 particles soaring to 200 per cubic metre of air - quadruple the safe levels of 50.

Phrae Governor Pongrat Piromrat said: ''We are working hard to reduce the air pollution but I am still not satisfied. Fire fighters will be sent to any locations where farmers are making fires and they will extinguish he flames.''

Governor Somsak Changtragul from Khon Kaen, another badly affected region, said: ''We have asked factories to blacklist farmers who bring in sugarcane that shows burn marks, a sign that the farmer set fire to his field at a time when the air pollution is serious.''

Pollution Control Department chief Phuwiang Prakammin said air quality around Bangkok had improved because breezy weather had blown away fine dust particles and smoke.

However,, the Meteorological Department warned Bangkok’s will worsen between February 13 and 15.