NEW DELHI, May 15: For the second time in ten days, more than 500 residents clashed with police in the Mohan Garden area of West Delhi on Thursday over the installation of power transformers. 20 people, including ten policemen, were hurt.Among those seriously injured were a five-year-old boy, Sudhir, and an assistant SI of the Delhi Police. Sudhir suffered head injuries and has been admitted to Safdarjung Hospital in a serious condition. While the police claim that he was injured in a road accident, angry residents accuse the police of resorting to a lathi-charge.The trouble began at 10.30 am today when the residents came out on the streets protesting against the delay in the installation of two transformers in the area - an issue which had lead to a massive demonstration on May 7.Over 500 residents gathered to stop traffic on the Najafgarh Road, demanding immediate installation of the transformers. An eye-witness said, the trouble began when the police arrived and resorted to lathi-charge. Whilethe police say that only 20 people were hurt, the residents feel the number is much higher. The police version is, however, different. According to them, before the residents reached the Najafgarh Road, they were stopped by police in riot gear and ordered to go back. But, the police say, the protesters replied by pelting bricks taken from a passing truck, which led to the situation worsening.Mukesh Sharma, Congress MLA from Hastal who has been on hunger strike since Wednesday to protest against the delay in installing transformers, says, "After the stone-pelting, the police went berserk,". While the residents allege that a rival political party workers had begun stone pelting the police to instigate them.