As a thick blanket of smog enveloped the airport, flights were delayed at Chennai airport on Thursday morning after visibility dipped to 250 metres.
Four flights - from Bengaluru, Thiruvananthapuram, Hyderabad, Mumbai and Riyadh - were kept on hold for more than ten minutes as they could not land.
The smog was caused by burning of bhogi bonfires as part of the Pongal festival.