The incident took place on Friday night, an hour before the second phase of the assembly elections was to begin.
Since the CCTV footage was available in the area, were scanned and it was suspected that it was done by two veiled people, who came in a two-wheeler.
When the crude blast triggered, nobody was injured.
According to the police investigation is underway.
Over six areas, the Polling of Assembly elections for the second and final phase in Manipur started at 7 am on Saturday in 22 constituencies.