VIRUDHUNAGAR: The Srivilliputhur Railway police registered a case against seven caste Hindus who were accused of inflicting knife injuries on a Dalit boy over previous enmity between the two community members belonging to Thiruthangal in Virudhunagar district. Sources said the 16-year-old Dalit boy, studying class XI in the a government school at Thiruthangal, was returning from Sattur along with his friend after attending a marriage function when he was allegedly attacked.