Pakistan blamed Diwali firecracker pollution drifting from India for Lahore's worsening air quality. The claim revived a cross-border dispute as Lahore and Delhi ranked among the world's most. Pakistan has blamed India's Diwali fireworks for Lahore's toxic air, but an independent assessment questions the claim and points to multiple pollution sources. Pakistan claims Diwali fireworks in neighbouring India caused toxic air in Lahore as the city ranked as the world's most polluted.