Kolkata: The Election Commission on Friday directed police across districts to take preventive action against potential troublemakers ahead of polls. The instruction came during a video conference with CPs and SPs, attended by police observers. The EC ordered to trace and put all with criminal records in jails or lock-ups by 72 hours ahead of polls. OCs and SDPOs were told to summon and warn habitual offenders and to take action if they didn't comply. tnn