Police used teargas and resorted to lathi-charge to disperse BJP leaders and supporters when they marched towards Kolkata Police headquarters Lalbazar demanding the release of students arrested during the Nabanna Abhijan rally on Tuesday. The rally was called for demanding the resignation of Chief Minister Mamata Banerjee in the wake of the recent rape and murder of a postgraduate trainee doctor at state-run R G Kar Medical College. The police action began after BJP supporters attempted to break police barricades to enter Lal Bazaar. BJP state president Sukanta Majumdar, who led the march, fell ill after being exposed to teargas and subsequently left the scene. Earlier a BJP procession led by Majumdar was stopped from advancing towards Lal Bazar. In response, Majumdar, along with local BJP leaders, sat in protest at the barricade around 4:30 PM, demanding that the police clarify their stance on the arrests and seeking unconditional release of the students arrested during the Naban