Bijnor (UP), Aug 8 : The search for two man-eater leopards has hit a snag due to the short battery life of thermal sensor-equipped drones. According to forest officials, of the total seven drones the forest department owns, the two recently bought ones have thermal sensors that allow them to spot any living object even if it is hiding under the deep covers of a sugarcane field. The key obstacle that the two unmanned aerial vehicles constantly face is their low battery life. Sub-divisional officer Gyan Singh, an official deployed to locate the leopards, explained that their batteries get discharged within 20-25 minutes of usage. 'Five-ten minutes go in the take-off and landing of the drones. That gives us about 15 minutes to operate the drones,' Singh said. 'While they manage to find their precise location, the drones cannot keep up with the animals due to their short battery-life and the operator has to fly them back,' added Singh. He said orders for batteries with better backup power have been placed. The search teams, meanwhile, spotted the two 'man-eater' leopards in Rehar area of the district on Monday. There, the animals hunted a goat placed as bait. A day after issuing kill orders for the two leopards, which have reportedly killed a dozen people and injured 50 others over the last seven months, the forest officials reiterated that their priority was to neutralise the animals and elimination was only a last resort. Senior forest officials from Lucknow and other districts are camping in Bijnor to monitor the search operation. /IANS