Villagers are being blamed for causing a wildfire that ravaged 290 rai of forest in Doi Suthep-Pui National Park and sparked smoke pollution concerns.
Commenting on Sunday's fire that took all day to bring under control, deputy Chiang Mai governor Mongkon Suksai said Monday an initial investigation found several villagers lit the fire to clear land to collect wild vegetables.
The fire caused extensive damage, essentially destroying 290 rai in the national park near the border between Muang and Mae Rim districts in Chiang Mai.
The villagers are accused of lighting fires in four locations at or about the same time, according to Chiang Mai anti-wildfire operations chief Phongphawat Yaiwongkon.
One fire was started west of the Chiang Mai International Exhibition and Convention Centre, another was lit near Ban Na Rai Luang and another erupted close to an orange orchard near Chang Khian boy scout camp. He did not say where the fourth blaze started.
The wrongdoers must be brought to justice, Mr Mongkon said, adding an investigation to find the culprits was under way.
Prime Minister Prayut Chan-o-cha commended the response by authorities in putting out the wildfire, which included dropping water from aircraft. However, he said more efforts must be made in fire prevention.
"It's not right to keep putting out fires," the premier said Monday. "It's about people's awareness."
Many villagers are poor and don't think of the impacts of trying to make a living by entering a forest, lighting a fire and then scavenging for something to eat or sell, Gen Prayut said. This is a root cause of the problem, he added.
The government needs to find ways to improve villagers' living standards as well as educating them about forest fires, which are a major cause of the haze problem in the North, Gen Prayut added.
Sunday's fire slightly increased the haze problem in Chiang Mai's Muang district, according to the Pollution Control Department.
Dust particles in the air as a result of the smoke exceeded the safety limit of 120 microgrammes per cubic metres, the Pollution Control Department said.
Elsewhere, firefighters are still battling fires that broke out on May 3 in the Bang Nara forest reserve in Sungai Kolok and and Sungai Padi districts of Narathiwat.
Winds are hindering efforts and fire breakers cannot stop "ground" fires, Natural Park, Wildlife and Plant Conservation Department chief Thanya Netithammakun said Monday. A ground fire is when peaty soil catches fire. At least 230 rai of forest is believed to have been destroyed.