Vehicles from both the states were stoned and burnt by protesters during Cauvery protests.
Doctors in Karnataka smuggled a desperately ill patient across the state border to Tamil Nadu under cover of darkness to receive a liver transplant after police said violent protests over the Cauvery water dispute would make the journey by ambulance too dangerous.
Police have halted traffic between Tamil Nadu and Karnataka after protesters angered by water shortages began rioting and torching vehicles.
The move forced doctors at a Karnataka hospital to come up with an alternative plan after a liver for transplant became available for their patient at a hospital in Tamil Nadu.
Arikichenin Olithselvan, a doctor at the Manipal Hospital in Karnataka, said they had to ditch their ambulance and wheel the 55-year-old man across the border before finding a local ambulance to ferry him on to the hospital where the operation would take place.
"We had to take out the patient from ambulance and put him on a wheel chair," he told AFP today.
"They (police) did not want to take (a) chance in allowing our ambulance with a serious patient cross the border."
Vehicles from both the states were stoned and burnt by protesters over the sharing of Cauvery water. Police have not even been allowing ambulances with Karnataka number plates to drive into Tamil Nadu.
The protests erupted after the Supreme Court ordered Karnataka to release water from the river to ease the shortage in Tamil Nadu until later this month.
Dr Olithselvan said the 12-hour transplant operation had gone well and the patient was recovering.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)