Four people have been arrested on charges of assaulting policemen manning the roads leading to a BJP rally attended by Prime Minister Narendra Modi on Monday.Sources said the incident occurred at Kharagpur’s Chowringhee crossing, when police personnel asked a number of BJP supporters to step off their buses and go the rest of the way on foot. This angered the party activists, who retaliated with force. As many as 14 policemen and civic volunteers were injured in the incident, video recordings of which have gone viral on the social media.Confirming the arrests, West Midnapore district police chief Alok Rajoria said the four would be produced in a local court on Tuesday. “An investigation is on,” he added.The incident was condemned even by Dilip Ghosh, president of the BJP Bengal unit, who stated that those involved in attacking policemen cannot be defended.Video clips of the incident show a handful of policemen being encircled by angry BJP supporters, who then proceed to rain blows on them with sticks and bare hands. Left with no other option, the policemen take to their heels. One is even thrown to the ground before he manages to recover and escape.Police said they asked the BJP supporters to walk the rest of the way because the roads leading to the venue had been clogged with traffic. A hunt is on for others involved in the attack.