Unidentified miscreants lobbed a crude bomb at the residence of expelled BJP leader Ch Bijoy in Lamphel area in Imphal West district in Manipur.
The incident took place on Friday night, hours before the second phase of the assembly elections was to begin, they said.
Nobody was injured in the blast triggered by two masked persons, who came in a two-wheeler, a police officer said as reported by PTI.
Bijoy, who was expelled from the saffron party last month for six years on disciplinary grounds, told reporters, "The attack might be a threat… to make me politically silent.”
Further investigation is underway, police said.
Polling for the second and last phase of assembly elections in Manipur began at 7 am on Saturday in 22 constituencies across six districts.
92 candidates are in fray for the second phase of polls. The areas in focus this time include the Thoubal district and the Naga-dominated hills where the ruling BJP faces a stiff challenge.
The districts, on the outer circuit of the state, have long been strongholds of the Naga People's Front (NPF) and the Congress, and have been hotspots of bandhs and blockades.
There are a total of 8.38 lakh voters in this phase in the districts of Thoubal, Chandel, Ukhrul, Senapati, Tamenglong and Jiribam, the officer said.
The BJP has fielded 22 candidates, followed by Congress (18), National People's Party (11), Janata Dal (United) and Naga People's Front (10 each).
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