Stones were hurled and several two-wheelers were set ablaze as supporters of BJP and TMC clashed in West Bengal's South 24 Parganas district on Saturday afternoon, police said.
The incident happened when a bus, in which BJP supporters were travelling to leader of opposition Suvendu Adhikari's rally in Diamond Harbour, was allegedly stopped by TMC activists in the Hatuganj area, around 40 km from Kolkata, they said.
As the BJP supporters got down from the bus and took on those who stopped it, a clash broke out with two sides hurling stones at the other, they added.
Two-wheelers parked on the roadside and a nearby TMC party office were torched as chaos reigned supreme in the area, a few hundred metres from the venue of the rally. A large contingent of the police soon reached the spot and brought the situation under control, an officer said.
BJP MLA Agnimitra Paul, who was in a vehicle behind the bus, joined the BJP supporters to block the arterial Diamond Harbour Road, a national highway, leading to a massive traffic snarl.
Claiming that her party's supporters were not behind the arson, Paul said, "TMC activists attacked our men. They are afraid of the popularity of Suvendu Adhikari and hence wanted to disrupt the rally. Our men were beaten up when they were protesting peacefully."
There were no reports of any casualty in the violence, police said.
Adhikari later addressed a mega rally in Diamond Harbour -- the Lok Sabha constituency of TMC's Abhishek Banerjee, in a show of strength ahead of the panchayat polls.
Apparently targetting Chief Minister Mamata Banerjee, Adhikari tweeted, "Your administration didn't allow the Rally at first. Hon'ble high court granted permission. You blocked roads, obstructed supporters from reaching the venue, disrupted arrangements and placed hurdles at each step. Your onslaught could not dent the determination of @BJP4Bengal karyakartas."
Hitting out at the BJP, TMC spokesperson Kunal Ghosh alleged that activists of the opposition party resorted to vandalism to divert attention from the "poor turnout" at Adhikari's rally.