The violence fanned out to Asansol areas, prompting police to suspend Internet services and clamp prohibitory orders under Section 144 of the CrPC in the trouble-torn areas of the district.
The Trinamool Congress won 211 seats.
"The post-mortem report said it was a case of asphyxia due to ante-mortem hanging and suicidal in nature," the SP said.
Mamata Banerjee's TMC and Kejriwal's AAP challenged the old order.
Chief Minister Mamata Banerjee directed the director general of police to instruct all the superintendents of police to take strong action against those who carried arms in the rallies.