Madhavi Adak, 43, mother of BJP worker Piru Adak was allegedly killed by the Trinamool Congress workers Tuesday in Hooghly.
The incident happened on the intervening night of Monday-Tuesday.
The Bharatiya Janata Party alleged the TMC workers were assaulting Piru when his mother intervened.
The BJP’s Goghat candidate Biswanath Karak visited the residence of Piru and demanded strict action against the perpetrators.
The third phase of voting for 31 assembly seats in Hooghly, Howrah and South 24 Parganas is underway in West Bengal.
The voting for 294 seats of the West Bengal assembly is spread over eight phases and the counting of votes will start on May 2.
The BJP has also requested the Election Commission for the deployment of additional central security forces for the peaceful conduct of the polls.