The attack took place on Monday evening when the boy had gone out of his home in Harinagri village to relieve himself while his mother was in the kitchen, Chief Conservator of Forest BP Gupta told PTI.
The leopard dragged the boy inside the forest surrounding the house. The next morning, his half eaten body was recovered by villagers 250 metres away, Mr Gupta said.
"Angry villagers numbering around 4000-5000 set on fire eight hectares of van panchayat land in the village yesterday," Mr Gupta, who is also the nodal officer for forest fires, said quoting Bageshwar Divisional Forest Officer RK Singh.
The fire could not be extinguished as irate villagers did not allow outsides to enter the village, he said.
"Since it was the second such incident in the area, the villagers may have burnt down the forest to clear the thickets and destory the big cat's hideout to save themselves," the official said.
According to Mr Gupta, the leopard has been declared a man-eater and an order to kill has been issued.