A stone was hurled at BJP's national vice president Kalraj Mishra when he was addressing a meeting at Dhurwa here but the stone hit the mike, party sources said.
However, it was not yet known who had hurled the stone, according to a police officer posted with the Dhurwa police station.
He said an FIR was being filed in connection with the incident.
Condemning the incident, BJP’s state unit president Dineshanand Goswami said, "I have informed the matter to the DGP and the SSP (Senior Superintendent of Police) and demanded immediate identification and arrest of the culprit."
Goswami, who was present on the dais, suspected that the stone was thrown by an activist of an opposition party.
Mishra was addressing the meeting, which was organised in protest against price rise, allotment of coal block and other issues.