Two buses carrying Bharatiya Janata supporters was allegedly attacked by Trinamool Congress workers in Bankura on Wednesday morning.
The supporters were on their way to Prime Minister Narendra Modi's rally in Kolkata's Brigade Parade Ground, when the buses were ransacked.
Angry BJP supporters protested at Bankura police station.
The PM kickstarted his election campaign in the TMC-ruled state from Siliguri on Wednesday. He's schedule to address another mega rally at the Brigade Parade Ground in Kolkata at 3 pm.
West Bengal, with a total of 42 Lok Sabha seats, sends the third largest number after Uttar Pradesh's 80 and Maharashtra 48.
The BJP, which clinched 17 per cent votes and two seats in 2014 national elections, has emerged as the second biggest party in the state.