The body of Rekha Devi, 30, was found Saturday in a field in Lahariyachak near Patna's Phulwarisharief, according to the police.
Police suspect political rivalry as a possible motive behind the murder.
Polling in five districts was postponed due to the fear of Maoist violence.
The multi-phased polls for 262,000 panchayat posts in 37 districts of Bihar will end with vote counting May 28.
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