By Azaz Syed, Lex Harvey, CNN

Islamabad, Pakistan (CNN) — At least 14 newborn babies died Wednesday morning in one of Pakistan’s deadliest hospital fires in recent decades.

The fire broke out inside the maternity ward at the government-run Pakistan Institute for Medical Sciences (PIMS), the largest hospital in Pakistan’s capital Islamabad, around 7 a.m. local time.

The blaze appears to have been triggered by an air conditioning compressor explosion inside the nursery where the newborn babies were being cared for, rescue sources told CNN.

Hospital workers were able to rescue one child, the sources said.

Outside the hospital, a grieving father told reporters his three-day-old baby had been killed in the fire.

“No one can understand the pain I’m going through,” he said.

A woman named Muneeba who was visiting family in the hospital described narrowly escaping with her nephew and sister-in-law as the fire began to spread.

“Thank God our baby is safe,” she told CNN.

Multiple people reported encountering locked doors in the ward.

Two sources at Islamabad’s Capital Development Authority (CDA) later told CNN that hospital authorities closed the facility’s main gates after the fire broke out, causing delays in the rescue operation. It’s unclear why this may have happened, but in previous emergencies, the hospital closed the complex to prevent any rush of family or visitors trying to reach patients.

Rescue personnel reached the hospital’s main gate within six minutes after being called at 6:54 a.m. local time, the CDA sources said, but it took additional time to open the gates. The gates were reopened with the assistance of local traffic police, but hospital security personnel then provided first responders with the wrong location of the incident, the sources also said.

A spokesperson for the hospital denied the claims of the gate closure, calling them “factually incorrect.”

Asked about the specific allegations, Pakistan’s Federal Health Minister Mustafa Kamal told CNN: “I am not aware of any such thing; however, an inquiry is going on which will determine the facts.”

Pakistan Prime Minister Shehbaz Sharif said he was “deeply saddened by this tragic incident” and extended condolences to the parents of the babies killed.

Sharif also ordered an immediate investigation into the fire, promised “strict action against anyone found responsible,” and suspended a top official in the country’s federal health department, Aslam Ghauri.

Health care in Pakistan is delivered through both private and public providers. Government-run facilities are chronically underfunded and short-staffed, and have faced criticism for aging infrastructure and lack of emergency preparedness.

Sharmila Sahibah Faruqui, a member of Pakistan’s national assembly, called the tragedy “shameful and unforgivable” in a post on X.

“Heads must roll. Please do not hide behind another inquiry committee,” she wrote. “Those responsible must be taken to task.”

Islamabad is home to Pakistan’s political and military elite and its facilities are generally of a higher standard than those found in other towns and cities in the country.

The PIMS facility is located on a sprawling site in the capital.

According to its website, its mission is “to be a premier research-intensive medical university that will educate medical students, paramedics, and postdoctoral fellows in accordance with international professional standards.”

Pakistan has experienced several major fires in recent years, including in hospitals, which often run on outdated electrical systems.

Earlier this year, a massive blaze at a shopping center in Karachi killed at least 67 people.

In June 2022, a fire broke out at a children’s hospital in Lahore and destroyed thousands of dollars worth of medicine, local media reported.