A poster with death threats to West Bengal Chief Minister and Trinamool Congress supremo Mamata Banerjee and her nephew, party's general secretary Abhishek Banerjee, appeared in Uluberia in West Bengal's Howrah district on Friday, police said.
The poster, handwritten in green ink on a piece of white cloth, was recovered from a construction site in Fuleswar area of Uluberia where Lok Sabha elections will be held on May 20.
The poster written in Bengali read: "I will kill Chief Minister Mamata Banerjee and Abhishek by hitting them with a car. Everyone will light the lamps after that. I have a secret letter."
The poster was found hanging on a stack of bricks.
"It is not yet clear what the secret letter meant. It could be a prank. We have to find out whether a single person or a group was involved in it," the police officer told PTI.
The police have started an investigation into the matter, he said.