Chennai, Nov 01: Police have filed chargesheets against four top state political leaders, including DMK President M Karunanidhi, under provisions of Tamil Nadu Essential Services Maintenance Act for allegedly instigating state government employees to go on strike, police said today. The chargesheets were filed under section five of the act, police sources said. Others against whom chargesheets have been filed are state congress working president E V K S Elangovan, CPI-M state secretary N Varadarajan and CPI state secretary R Nallakannu, the sources said. The employees had gone on an indefinite strike in July demanding restoration of curtailed benefits. Bureau Report