Villagers were baffled by this mysterious smoke which has been rising from the ground for the last five months.

Pattama Pimsali, 62, first noticed the mist coming from under her field in Udon Thani, northeastern Thailand in February.

The landowner attempted to pour water directly into the spot worrying that it could become a bigger fire but the smog was still rising.

The unstoppable underground fire has killed her plants and destroyed soil nutrients, which also made the unpleasant atmosphere for the last five months.

Pattama said: ''My cow was once burned on his leg because he walked into the area while eating grass. The fire is getting bigger and keeps burning my land.

''The smoke has a strong smell too, like a chemical. It'll hurt your nose when you breathe it in for too long.''

Footage taken yesterday (July 11) shows how more white smog was flaring up when Pattama began poking the dark, solid ground.

Prasert Chantawan, the chief of Chiang Phin village, also shows in the video how the heat turns a raw egg into the soft-boiled after leaving it on the spot for ten minutes.

The village chief said environmental officers were informed and had visited the field but none of them could solve the problem and seemed to know the cause of the fire.

He said: ''They came with two big pumps and spent all day putting a large amount of water. But it still didn't help.

''All we can do now is to alert our people and make sure anyone didn't get close to the area. I just hope that the fire would stop spreading otherwise it would totally affect our daily lives.''