A doctor who was attacked by a patient he had treated more than 20 years ago was still in critical condition after eight hours of treatment on Friday afternoon.

According to the Guangdong General Hospital in Guangzhou, Guangdong province, the hospital is organizing senior experts and doctors to help save Chen Zhongwei, who is in the intensive care unit for further medical observation and treatment after surgery.

"Doctors are doing what they can to help rescue Chen," said a statement from the hospital.