Pakistani Prime Minister Shehbaz Sharif has suspended a top health official after 14 newborn babies died in a fire in the maternity unit of an Islamabad hospital.

The fire reportedly broke out in an air-conditioning unit at the state-run Pakistan Institute of Medical Sciences hospital late Tuesday night. The flames were quickly ignited by oxygen connections.

According to the BBC, of the 15 babies on the ward at the time, one newborn has been rescued.

An investigation is under way, with a committee ordered to report within 24 hours.

The father of a victim has criticised the safety measures at the hospital, saying only one door was open for visitors.

Families have gathered outside the hospital, many in tears.