Departure of almost all early morning flights was delayed as 'smog type of fog' induced by the presence of soot in the atmosphere reduced visibility to as low as 300 metres at 6 am, Airport Meteorological Director Dr N Jayanthi told PTI.
The soot was caused by people burning old clothes, papers and tyres as part of tradition on the occasion of Bogi Festival, which marks the beginning of Pongal festival.
The flights which were delayed included the Indian Airlines airbus 300 and Jet Airways flight on Chennai-Delhi sector.
The IA flight, which was scheduled to leave at 6.40 am, left at 9.15 am, a delay of 145 minutes, while the private airline flight was delayed by 165 minutes.
Suburban train services also operated at a lower speed for about two hours due to poor visibility.

Bureau Report