Over 2,000 employees of various companies, including Information Technology major Tata Consultancy Services, formed a human chain along a three kilometer stretch on the Rajiv Gandhi Salai (IT-Corridor) here.
They held placards with slogans against using drugs, its abuse and dangers.
Similar human chains, rallies, seminars, awareness camps, involving students and youngsters, were held in 22 districts, a police release said.
The events were organised by the Narcotics Intelligence Bureau CID in association with Anti-Video Piracy Cell of the State Police and top officials participated.