With four children dying in a government-run hospital here within 24 hours opposition in Tamil Nadu on Saturday hit out at the callousness of the state health department and demanded the state government accept responsibility. The children aged between eight and 11 died due to mysterious fever at the Institute of Child Health and Hospital for Children here since Friday. Its Resident Medical Officer was not available for comments despite several attempts by IANS. Read: Hospital death risks higher during weekends. In a statement issued here Leader of the Opposition in the Assembly M.K.Stalin condemned the Tamil Nadu government for