Members of the scheduled caste wing of Tamil Nadu Congress Committee (TNCC), led by K Selvaperunthagai, tried to picket the Shastri Bhavan here, which houses a number of central government offices.
About 65 Congress workers were detained, police said.
The protesting Congress workers sought a CBI probe into the death of Rohith Vemula, a Dalit scholar of HCU, who was found hanging at the central varsity's hostel room on Sunday.
Members of SFI, affiliated to CPI (M), also staged a protest demonstration.
More From This Section
(Reopens MES8)
DMK President M Karunanidhi sought legal action against those behind the suicide of Vemula.
"It is the expectations of all that there should be just legal action against those behind the suicide of the Dalit student," he said in a statement.