Soldiers today continued battling raging forest fires ripping through Chiang Mai province in northern Thailand.

Around 90 troops and firefighters were dispatched after a fire broke out at the Doi Suthep-Pui National Park at around 8:30 PM on March 30. The personnel struggled to control the blaze due to poor visibility at night, steep cliffs, and heavy winds that fanned the flames.

Kritsayam Kongsatri, director of the Protected Area Regional Office 16 in Chiang Mai, said today that authorities were requesting helicopters to dump water on the wildfires.

He said that a raging fire at the Pha Daeng National Park has been extinguished after five days, with reconnaissance teams and wildlife staff monitoring the area for potential reignitions.

He added that a fire in the Mae Takhrai National Park is expected to be extinguished today, while nine hotspots were being tackled at the Srilanna National Park.

The Geo-Informatics and Space Technology Development Agency on Wednesday detected some 343 hotspots in northern Thailand.

Around 1,670 firefighters have been deployed to keep the fires at bay.

Northern Thailand has been grappling with hundreds of forest fires in recent weeks. The flare-ups are believed to be caused by agricultural burning, as farmers cheaply clear their land by setting ablaze waste crops.

It has led to soaring levels of harmful PM2.5 particles in the atmosphere, with air pollution in Chiang Mai and Chiang Rai the worst in the world this week.

As of March 31, Chiang Mai ranks the worst city in the world for air quality, Swiss air monitoring company IQAir said. It had a 'hazardous' 331 US air quality index, with a PM2.5 reading of 280.7 micrograms per cubic metre. The safe level in Thailand is 50.