Bhopal, June 19 :    Bhopal, June 19:  A section of old Bhopal turned into a battlefield this afternoon when more than 500 people turned violent while protesting against the screening of Gadar, a film starring action hero Sunny Deol and Amisha Patel. Released last Friday, the film tells the trauma of Partition through a love story of a Sikh boy and a Muslim girl. The armed protesters swooped down on a 100-strong police contingent positioned outside a cinema hall screening Gadar and a fought a pitched battle. They went on a rampage, throwing stones, bombs and Molotov cocktails, and torched more than a dozen two-wheelers and smashed 10 cars. Finding themselves outnumbered, the policemen fired teargas shells to disperse the mob. They failed, and were forced to run helter-skelter for shelter. Two policemen were injured, one of them critically. Superintendent of police Arun Pratap Singh said the protesters had tried to sever the arm of a policeman with a sword. He is in hospital and doctors are trying to save his arm. The rioting continued for more than two hours this afternoon and ended only when the 800-strong audience bottled up inside the hall rushed out. The agitated viewers chased away the trouble-makers. Before disappearing, however, they threw a stone wrapped in a piece of paper at the police superintendent. It was an anonymous letter, threatening that if Gadar continued to be screened tomorrow, Lily Talkies, the only cinema screening the film in Bhopal, will be bombed. Trouble started here last night when Arif Masood, a local Youth Congress leader, met the collector and police superintendent and warned of repercussions if Gadar was screened. Masood also submitted memoranda to the district authorities. Apprehending trouble, the police had posted 100 policemen outside the hall, where screening started as usual for the morning show from 11. The show was on at a little after one, when the protesters wearing black turbans began collecting before the hall. Shortly afterwards, they dispersed for a prayer meeting. The police contingent failed to smell trouble. The district police headquarters had no inkling of events to unfold when at 1.30 pm, a senior police officer called the police control room for intelligence information. The officer was told all is well. However, 15 minutes later, the armed mob re-assembled outside the hall and all hell broke loose.