A probe is underway after a fire ravaged a hospital in Beijing, the capital of China, killing 29 people, as per local media.

Emergency response teams first received a call before 1:00 pm (0500 GMT) Tuesday that a fire had torn through Beijing Changfeng Hospital in the capital city's Fengtai District, as per reports.

Approximately 30 minutes later, the fire was extinguished. Rescue operations lasted for another two hours, during which 71 people had been reportedly rescued.

Social media users circulated videos on Tuesday of people sitting on external air conditioning units, as others were clinging to ropes and jumping off the building.

#China. #Tragedy.21 people died in a fire that broke out today in a hospital in #Beijing.71 patients were evacuated from the facility.The fire was completely put out by the firefighters,while the authorities have opened an investigation to reconstruct the dynamics of the accident pic.twitter.com/80mGl2BeOC

— Donato Yaakov Secchi (@doyaksec) April 18, 2023

Leading municipal officials paid a visit to the hospital soon after the incident, with Beijing party secretary Yin Li promising to "quickly identify the cause of the accident and hold the relevant responsible persons accountable," as per the Beijing Daily.

12 people, including the facility's director, have been detained in connection with the fire, confirmed Sun Haitao from Beijing's public security bureau, adding that representatives from a company renovating the hospital were among those being held.

The victims were 16 women and 13 men, Yin affirmed.

State broadcaster CCTV reported that a preliminary probe revealed the blaze had been caused by "sparks generated during the internal renovation and construction of the inpatient department of the hospital."

The sparks "ignited the volatiles of the flammable paint on the site," CCTV said.

The broadcaster reported that out of the 29 dead, 26 were patients at the hospital, two were hospital staff and one was a patient's family member. 

There were still 78 patients being treated at the hospital, who have been moved to the facility's west building, CCTV added.

State-run People's Daily reported that as of Wednesday morning, 39 people were being treated in the hospital with injuries, while three had been discharged.