Additional Deputy Commissioner of Police Parmpal Singh said the incident occurred when 70 groups of 'Nihangs', consisting of over 2,000 participants from all over Punjab, were taking part in a horse race and displaying tricks on horse back.
Every year, as per Sikh community tradition, on the next day of Diwali, 'Nihangs' gather in open ground of Gurdwara Shaeed Ganj to display their skills to public while moving on the back of horse carrying weapons, Singh said.
Heavy police force was deployed keeping in view of display of fire arms, including weapons by Sikh outfits.
The moment gun shots were fired, police swung into action and overpowered all the accused involved in the crime from both sides, he said.
He said more than twelve 'Nihangs' have been arrested, including key accused Sher Singh and Pritam Singh from different groups of the sects.