Prime Minister Narendra Modi arrived in Coimbatore on a day's visit.
Around 160 people were detained by Coimbatore police on Tuesday for staging a black flag demonstration against Prime Mnister Narendra Modi's visit to the city.
The protesters raised slogans against Prime Minister Modi and Union Labour Minister Bandaru Dadattreya and demanded a judicial probe into the suicide of Dalit scholar Rohith Vemula at Hyderabad Central University campus.
The protesters, who were part of a federation of 45 students, Dalit and youth organisations championing the cause of Rohith Vemula, blamed the central government for the death of the research scholar.
"The Centre is encouraging educational institutions and central institutions to gradually come under the grip of ABVP and Hindutva forces. Rohith was continually threatened, harassed and was driven to suicide. We demand the dismissal of Union Ministers Smriti Irani and Dadattreya", said one of the protesters.
Prime Minister Modi arrived in Coimbatore on a day's visit after participating in an Ayruveda conclave in Kerala. He also inaugurated the ESI medical College and Hospital in Coimbatore.