An abandoned tiffin box stuffed with some crackers triggered panic near a polling booth at Pirakata in Maoist-hit West Midnapore district on Thursday.
As soon as the news spread, police rushed to the area and found some crackers inside the tiffin box that was removed, the state's IGP (law and order), Raj Kanojia, told PTI in Kolkata.
Polling was, however, not disrupted, he said.
The police and para-military forces were keeping a strict vigil in the entire district, particularly the areas where the Maoists have threatened to disrupt polling and called for a vote boycott.
Meanwhile, a Congress worker was arrested at Taldangra in Bankura district on the charge of damaging an EVM.
Voters boycotted polls at Saidpur and Kumarganj in Balurghat Lok Sabha seat in South Dinajpur district demanding inclusion of the areas into North Dinajpur district.