Though there was no specific threat to the State, more than one lakh police personnel have been deployed on security duty as part of security arrangements, police sources said.
About 15,000 cops would be keeping a strict vigil against the movement of anti-social elements in Chennai city, apart from deployments of 1,200 Central Security Force personnel and four companies of Rapid Action Force.
A five-tier security arrangements has been put in place at the Chennai domestic and international airport, where the entry of visitors was banned till August 20.
All the vehicles entering the airport were subjected to thorough checks and passengers with valid tickets alone were allowed entry after verifying their identities.
Police have also intensified vigil at all important places like, commercial establishments, shopping malls, amusement parks, where public would throng in large numbers.
Checks were also intensified in hotels and lodges to check whether any outsiders were staying.
Barricades have been erected in various parts of the city as part of intensifying the vehicle checks.
The police have also instructed the public to alert the local station if they spot people moving under suspicious manner.
The Intelligence department was put on high alert and reports were gathered on to gauge the ground situation, especially in the context of the arrest of some suspects, said to be sympathisers of ISIS in Coimbatore and its surrounding areas.
All the vehicles entering and leaving the city were thoroughly checked as part of hightened security measures.
Security was also beefed up in all Railway stations, including the ever crowded Chennai Central and Egmore stations and passengers were allowed pass to metal detectors.
The baggages of the passengers were also being scanned thoroughly before they were allowed to board the train.
Several arterial roads have been under round-the-clock surveillance, with police installing CCTV cameras to monitor the movement of anti-socials.
Apart from police personnel in uniform, those in plain clothes were also deployed on security duty.
Similarly security was tightened across the state also.