Three vehicles including two of police were also damaged in the incident, Additional SP Dashrath Singh said.
"Elected Panchayat Samiti Members were coming to vote for the election of Pradhan in Khandar Panchayat when the mob of unidentified persons pelted stones at them. Policemen were also present there and they also received injuries," he said.
The officer said that three persons were rushed to Sawaimadhopur district where one man was declared dead.
Singh said that it was not clear whether anyone from the mob opened fire also or not. Additional policemen have been deployed in the area to maintain law and order, he added.