The incident occurred when some people blocked the Pulwama-Srinagar road at Pahoo bridge in view of a shutdown call given by separatists, they said.
They threw stones at vehicles. Sibti Hyder was seriously injured in the incident, a police spokesman said.
He was rushed to the district hospital, Pulwama, from where he was referred to the SMHS hospital in Srinagar in a critical condition, he said.
A case has been registered against unidentified men in connection with the incident.