CHENNAI: The six-day-old stir over jallikattu turned violent today after an early morning crackdown on the protesters here, leaving over 20 police personnel injured even as the Tamil Nadu assembly moved swiftly and passed a bill replacing an ordinance for conducting the bull taming sport.

A senior police official said that 90 per cent of the protesters at Marina beach, the epicentre of the agitation, predominantly by students and youth, had vacated the area by late evening and that normalcy was being restored.

Reports said most protestors in other parts of the state like Madurai, Erode and Coimbatore were either evicted or had left on their own, heeding the appeal of police.

However, the crackdown had a ripple effect in the city and elsewhere, where normal life was affected, with protesters staging road blocks and state transport buses being withdrawn at many places.

The government moved quickly to get the amendment bill to replace the jallikattu ordinance promulgated two days ago, passed in the assembly in the evening session.

The "Prevention of Cruelty to Animals (Tamil Nadu Amendment), Act, 2017", piloted by Chief Minister O Panneerselvam, was passed by voice vote with the support of opposition DMK and other parties.

It said the "Government of Tamil Nadu has decided to exempt jallikattu from the provisions of the Prevention of Cruelty to Animals Act."

On an eventful day, police set on an early morning crackdown at Marina after issuing an advisory asking students to leave.

They said students' protests had been successful as jallikattu had been held yesterday following the state issuing the ordinance.

Former Madras High Court Judge Hari Paranthaman also spoke to the protesting youngsters, explaining to them the technical specifications of the state government's amendment to the PCA Act.

According to a senior police official, "90 per cent of the protesters at Marina Beach have left."

Earlier in the day, protesters fought pitched battles with police at several areas, especially around Marina Beach from where thousands were evicted.

They blocked roads at various parts of the city with the week-long agitation taking a violent turn.

Traffic was thrown out of gear as the agitators took to the streets, with some attacking policemen and their vehicles.

Police fired teargas shells and resorted to lathicharge at some places as sections of protesters, removed from Marina in the early morning crackdown, pelted stones.

They went on a rampage, setting vehicles on fire at a few places, including in front of Ice House Police Station near the beach.