(CNN) -- A woman who went to visit her brother at a hospital in eastern India was gang-raped by six men Sunday night, police said. It's the latest in a string of such brutal attacks in the country. On her way home from the hospital, the 25-year-old woman was taken by two hospital custodians to a river bank where she was sexually assaulted by the pair and four other friends, said B.K. Aich, a police superintendent in Mayurbhanj District in Odisha state. All six were arrested.