The clashes occurred ahead of the panchayat polls in West Bengal. The panchayat polls will be held on May 11, 14 and 18. Counting will take place on May 21. On Friday, Trinamool Congress activists surrounded the Nandigram police station to protest the arrest of three party activists for their alleged involvement in the killing of a CPI-M Panchayat Samiti member last year. The Trinamool Congress had alleged on Thursday that its three candidates for panchayat elections were missing from Khejuri.