According to initial reports, Nimbalkar was proceeding on foot to address an election rally for the local Shiv Sena candidate Kailash Patil when a youth suddenly came towards him from the crowd.
Nimbalkar reportedly sustained a minor injury in his hand, and party leaders assured that he was not in danger, Sena Deputy Leader in Maharashtra Legislative Council Neelam Gorhe said, quoting preliminary information.
Eyewitnesses said that an unknown youth approached Nimbalkar ostensibly to greet him, but caught Nimbalkar's hand, tried to push him down and then attacked him with a knife.
Taken aback by the assault, Nimbalkar attempted to duck, but in the process sustained minor injuries on his hand and wrist.
Some supporters immediately rushed to his help and others made an attempt to chase the assailant who managed to flee.
"I am safe and secure after this dastardly knife attack on me. Fortunately, the injuries are not serious. I appeal to the Shiv Sena-Bharatiya Janata Party workers, all my supporters and well wishers to remain calm," Nimbalkar said in a statement soon afterwards.
To a query, the visibly shaken leader said he had "no idea who the assailant was or what his motives were".
He added that barely a few more days are remaining in the election campaign and appealed to the party workers not to get diverted by this incident.
( With inputs from IANS )