Heavy smog blanketed the Thailand capital on Wednesday, forcing authorities to shut down more than 400 schools.
Air quality in Bangkok climbed to an "unhealthy" 170 on Tuesday morning.
"We cannot simply put the blame on people and penalise all the polluters because the outcome of penalty measures will create other serious problems for society," Prime Minister Prayuth Chan-ocha told reporters.
Some officials claimed it's a "cocktail of factors" with unregulated burning of sugarcane crops being the main polluter despite the ongoing two-month ban.


Trump says Iran war deal close as Strait of Hormuz tensions linger
Fire breaks out at New Zealand's Wellington airport, disrupting flights
Ukraine and Russia trade overnight drone strikes, officials say
UN says Taliban arrest 30 women for violating hijab rules in Afghanistan
Trump cancels US strikes on Iran, citing progress in talks
