Although the West Bengal State Election Commission had deployed drone cameras for the surveillance of the city as it went for the Municipal Corporation polls here on Saturday, there was a three-hour delay in putting them to use. While the WBSEC had acquired one drone for the day from a company approved by the Election Commission of India, three were put to use by the Kolkata Police. However, the drones were used later in the day, after reports of violence started pouring in. “We were yet to take a final decision on the longitude and latitude of the places where the drone cameras would be used which is why their operation was delayed,” State Election Commissioner S. R. Upadhaya said.