Karachi- A doctor was critically injured in a knife attack by the unidentified man during the duty inside the Outpatient Department (OPD) of Civil Hospital Karachi on Tuesday. Sources of the hospital said Dr Maqsood, 33, was examining a patient in the OPD when the attacker stabbed him with knife and fled. The doctor was critically injured and taken to the operation theater for medical assistance. They said incident was reported at about 12:00am when the man attacked Dr Maqsood in ENT OPD. He was shifted to Operation Theater and his condition was stated to be critical, sources added. Sources said in past, a group of students of a nearby college and university were involved in the harassment of doctors, paramedical staff, visiting patients and this group may be involved in the attack on Dr Maqsood. The law enforcement agencies and private security guards hired by the CHK have failed to control crime inside the hospital. Medical Superintendent CHK Prof Dr M Saeed Qureshi, when contacted, said Dr Maqsood was shifted to the ICU and his condition was stable now. He said police have started investigation into the case.