The blast, which did not cause any casualty, took place at Imphal's locality of Uripok Yambem Leikai at around 7:30 PM, a senior police officer said.
A team of Manipur Police, led by Imphal West SP, visited the site to conduct further probe.
The reason of the attack is not known and no outfit has claimed responsibility so far.
B B Sharma had served as the Joint Director of Regional News Unit of All India Radio, Imphal before he retired and joined BJP.