A medical oncologist at the Kalaignar Centenary Super Speciality Hospital here was stabbed seven times on Wednesday by the son of a patient allegedly over grievances on treatment to his mother at the same facility, a hospital official said.

The man assaulted the doctor inside the Outpatient room during a conversation on treatment to his mother and he was apprehended immediately by staff and handed over to police who are questioning him. The doctor is being treated and he is stable, the official said.

Government doctors, strongly condemning the attack, announced a strike and Health Minister Ma Subramanian is said to hold talks with them.

The assailant has been identified as Vignesh, a resident of a suburban neighbourhood. His mother Kanchana was the patient. The victim was Balaji, a renowned oncologist and serving as associate professor in medical oncology in the government hospital.

"He closed the OP room and stabbed the doctor in his neck, behind his ear, chest, forehead, on his back, head and stomach. There was a huge blood loss. Already he is a heart patient and he had undergone a surgery for his heart ailment,' the official, an emergency medicine anesthesiologist, told reporters.

Claiming that he wanted to talk about his mother, Vignesh entered the OP room and since the door was closed it could not be opened immediately and later with the help of security personnel, staff and others, the doctor was brought out.

The oncologist, who had also undergone pacemaker implantation was resuscitated and immediately operated upon by a multidisciplinary team of surgeons.The victim bled excessively and his medication for his heart ailment is the likely reason for more blood loss. Two units of blood was transfused and all wounds were sutured. "We have to wait and see for another six to eight hours for his recovery; the oncologist is under anaesthesia."

"Balaji sir is a very sincere doctor and as of now he is stable and we pray to God that he will come back to normal condition."

The official said the assailant claimed that his mother was provided chemotherapy six times in the hospital she was later shifted to a private hospital where they said that her lungs were affected and what exactly transpired between the victim and assailant is not clear.