At least 15 infants were killed when a fire broke out at a state-run hospital in Pakistan's capital city, Islamabad, triggered by a fault in the air conditioning system, local broadcaster Geo TV reported on Wednesday.

The fire, which broke out at the Pakistan Institute of Medical Sciences (PIMS) hospital, started around two hours ago, the broadcaster said, adding that "cooling operations" were ongoing.

There were 16 newborns at the hospital's gynecology ward when the fire broke out, one of whom was rescued, according to Geo.

This is a developing story.