According to IG (law and order) R K Vishwakarma, the incident happened following a dispute between head constable Mukund Yadav and constable Sunil Dixit, both of 10 Provincial Armed Constabulary(PAC) who were on duty for the Uttar Pradesh Udyami Mahasammelan.
Vishwakarma told reporters that after the programme was over at Indira Gandhi Pratishthan both the jawans clashed during which they exchanged lathi blows, he said.
Vishwakarma said both the PAC jawans have been arrested by SSP Lucknow.
"A report is being sent to Commandant 10 PAC and they will be terminated from the service after departmental action. Misconduct and indiscipline will not be tolerated," he said.
Vishwakarma said the attack was sparked by an exchange of words between the two policemen apparently over some duty positioning issues.