Senior Bharatiya Janata Party (BJP) leaders, including former Bengal minister Suvendu Adhikari, youth morcha leader Shanku Deb Panda and Shibaji Sinha Roy were allegedly attacked by Trinamool Congress workers in Kolkata on Wednesday.
Roy, who is the president of the BJP's Kolkata North unit, reportedly suffered serious injuries and was admitted to Apollo Hospital in the city.
The incident happened in the Phoolbagan area of the city when the BJP leaders were going to the deputy commissioner's office.
Adhikari alleged bricks were thrown at him by TMC workers.