At least one people was killed and another five were injured Friday in a shootout at a main hospital in Islamabad, witnesses and hospital sources said, Xinhua reported.
Some unknown armed men opened fire at the emergency ward of the Pakistan Institute of Medical Science (PIMS), witnesses told Xinhua.
Three of the injured are also in a critical condition, the hospital said. The patients from the emergency ward have been vacated and the police has started search in the hospital.
A police spokesman said that one of the shooters has been arrested and police has cordoned off all main routes.
He said the police is determining whether it is a terrorist incident or group clash.
Witnesses said they were somehow shocked by such a rare incident happening in the heavily-guarded capital city.