Kolkata, May 10: The Election Commission has filed an FIR against Left Front chairman Biman Bose. The EC had alleged yesterday that the CPI-M leader was intimidating EC observers in West Bengal. Bose had apparently asked his party workers to stop EC observers from overstepping their brief, a statement viewed by the Commission as a serious violation of election rules. The EC said that Bose incited his party workers to create disturbance and prevent election observers from performing their legitimate duty in the state. Bureau Report