Demonstrators, mostly students, thronged the busy Marina Beach area in the city of Chennai in Tamil Nadu state to demand the lifting of the ban on the traditional Jallikattu event which is held during the winter harvest festival.
Authorities ordered over two dozen colleges in the city to close down on Thursday as the crowds swelled at the main protest site in the capital.
"We are protesting against the ban and demand that it should be immediately lifted. We are here in support of preserving the culture of Tamils," Selva Kumar, a student leader at the protest site, told AFP.
The protesters in Chennai, who began gathering on Tuesday night, say they will camp out until the authorities announce that the event will be allowed in future.
India's Supreme Court outlawed Jallilkatu last year after a plea by animal rights groups which have long argued that the event -- held every year in different parts of Tamil Nadu state -- is cruel.
Unlike in traditional Spanish bullfighting, the animals are let loose into open fields and young men then compete to subdue them bare-handed.
Critics say organisers lace the bulls' feed with liquor to make them less steady on their feet and chuck chilli powder into their faces to throw them into a sudden frenzy as they are released from a holding pen.
The rights group PETA has released footage it says shows bull farmers doping their animals ahead of the event.
But organisers of the festival insist the animals suffer no harm and Jallikatu is an established part of Tamil culture.
Tensions have been escalating for the last week after hundreds of people were detained by police for allegedly organising local Jallikatu contests in defiance of the court ban.
Police say the protests have remained peaceful so far but have spread to large parts of the state.
Several popular Tamil film stars have voiced their support for the demonstrators as has India's leading spin bowler Ravichandran Ashwin.
Opposition and ruling parties in the state have also criticised the ban and want Prime Minister Narendra Modi's government to have it overturned.
A government led by Modi's predecessor did order a ban in 2011 but it was effectively ignored until last year's Supreme Court ruling.
Tamil Nadu witnessed large scale protests by students in 1960s over the imposition of Hindi as the official language in the southern state, with the majority Dravidian community fiercely opposing it before the order was rolled back by the central government.
The state's chief minister O. Panneerselvam will be flying to New Delhi late Wednesday to meet Modi, as many fear the protests may snowball into a major agitation.
