At least 14 infants have been killed after a fire broke out at a state-run hospital in Pakistan's capital city Islamabad, triggered by a fault in air conditioning systems, according to local broadcaster Geo TV.The fire, which broke out at the Pakistan Institute of Medical Sciences (PIMS) hospital, started about two hours ago, the broadcaster said, adding that "cooling operations" were ongoing.There were 16 newborns at the hospital's gynaecology ward when the fire broke out, one of whom was rescued, according to Geo.Pakistan's Prime Minister Shehbaz Sharif has directed authorities to conduct an immediate investigation.