Are Pakistan's crop fires behind Delhi's toxic pre-Diwali air?

Delhi's air quality deteriorated sharply into the 'very poor' bracket ahead of Diwali, recording an AQI around 330 while multiple stations hit 'severe' levels over 400. Though stubble fires in Punjab dropped, satellite readings showed Pakistan's Punjab logged 13,241 fire detections, over 4.2 times higher than Indian Punjab. Experts say, northwesterly winds can carry smoke across the border.