Seven people have died in rain-related incidents in the state in the last 24 hours as the North East Monsoon continued to lash several districts.

No relief is expected anytime soon. The MeT department has warned of very heavy showers over the next 24 hours in Chennai, Kancheepuram and Vellore districts due to the formation of a new trough of low pressure in the Bay of Bengal.

Chennai has received 14.9 cm of rainfall since last night. Incessant rain has caused water-logging in parts of Chennai including St Thomas Mount, Velacherry, Anna Nagar and T Nagar.

Rail tracks have also been submerged at many places, resulting in delays in arrival and departure of trains at the Chennai Central Station. As many as 26 flights have been delayed.

Schools and colleges in Chennai, Vellore, Thiruvallur and Kancheepuram were ordered to remain close following the Met department's forecast.

This was the third time that a holiday has was declared for educational institutions in Chennai since November 9, when a deep depression over the Bay of Bengal crossed near the Tamil Nadu-Puducherry coast, resulting in heavy rain and consequent flood in many parts of the state. Cuddalore, 180 kms from Chennai, was the worst hit.

Office-goers had a harrowing time in Chennai this morning as they waded through knee-deep and waist-deep water in many areas. Hassled residents posted pictures of waterlogged roads on Twitter, making #chennaiRains a top trend this morning on the micro-blogging site.

"When chennai has more water ways than Venice and more waves on the roads compared to Bay of Bengal. #chennairains," posted @vasudevan_k.

"Don't know about flying cars but we need hover floating convertibles in Chennai soon ... #chennairains," wrote @amdbabu.