BEIJING (Reuters) - Chinese police have arrested a young couple who buried an old woman alive believing she was dead after their car hit the 68-year-old, newspapers said on Thursday, in a case which has sparked outrage over declining public morality. The couple had been at an all-night karaoke session when they hit the woman while driving in the early hours of the morning in the wealthy eastern province of Zhejiang last month, the official China Daily said. "A witness said he heard someone crying and saw an elderly woman lying on the ground near (the car)," it cited a policeman as saying. "A man and a woman got out and put the elderly woman in the car, saying they would send her to hospital." But, worried about being arrested for drunk driving and causing the accident and believing she was no longer alive, they buried her near the side of the road, the report added. However, when police later found the woman's body they discovered she was still alive when she was buried, and had then suffocated to death, the paper said. The story has been widely discussed on China's popular Twitter-like service Weibo, where it has ignited uproar for what some called the immorality of modern Chinese society. "Such things show that our society really has huge problems it is not facing," wrote one user. "People of China, how have you come to this?" wrote another. China's economic boom and the growing disparity between the rich and poor have made changing social values a contentious topic, with some lamenting what they see as materialism and a get-rich-quick attitude replacing public morals. Last year, graphic video footage of a two-year-old child run over by a van and ignored by passersby in southern China sparked similar anger.