Police said in the last few days, messages were being circulated in the social media "requesting youth to congregate at the Marina for various purposes".
"The youth and student community are requested not to believe such messages being circulated," police said in a release.
Marina was a place where families came in large numbers for recreation and relaxation and "for more than a decade protests, demonstrations and agitations have been totally banned in the entire stretch of Marina beach commencing from Light House to Napier Bridge," it said.
Police have identified several places in the city for political organisations and outfits for the "democratic expression of grievances", it said, adding permission is sought by those concerned before holding agitations and protests.
"In the light of the above, the Commissioner of Police (S George) has appealed to the citizens of Chennai to abide by the restrictions already in place with regard to the conduct of agitations etc at Marina beach. Miscreants and rumour mongers are also severely warned that stringent legal action would be taken against those persons who illegally congregate at the Marina beach," it added.