Extending recent erratic weather patterns, China has been hit by sudden freezing temperatures and heavy snowfall.

Authorities in the Chinese capital said on Friday that 102 people had suffered broken bones. The accident happened in west Beijing on an above-ground portion of the sprawling Changping subway line on Thursday evening.

China has been in the grip of harsh winter weather over recent days. Snow has been building in Beijing since Monday, with temperatures expected to slide further to minus 12 degrees Celsius (10.4 Fahrenheit). Further north, cities such as Shenyang could drop to a 2023 low of minus 27C (minus 16.6F), state broadcaster CCTV said.

Due to the weather conditions, slippery tracks prompted a braking on the leading train. The train following from behind was on a descending section and went into a skid and was unable to brake in time, the city transport authority said in a statement on social media.

Emergency medical personnel, police, and transport authorities responded, and all passengers were evacuated by about 11pm.

By Friday morning, 423 people had been released from hospital, 25 passengers were under observation and 67 remained hospitalised. No deaths were recorded.

On social media, images of the collision showed passengers on the floor and partial lighting outages. Some commuters used emergency hammers to try to break the train windows to escape.

In other videos, firefighters were seen helping to evacuate an elderly passenger while others made their way through the deep snow to leave the scene.

“We sincerely apologise for the accident that occurred this evening,” Beijing Subway, the train’s operator, said on the Weibo social media platform.

“Passengers who left the premises unaccompanied during the evacuation and who are not feeling well can contact us at any time. We will take on the cost of care,” it added.

Alerts remain in place in Beijing for icy roads, extreme cold and heavy snowfall. Temperatures were due to fall to minus 11C (12F) overnight on Friday.

The heavy snow began falling in Beijing on Wednesday, leading to the closures of schools and train operations. However, no deaths have been reported from the winter storms that have hit a large portion of northern China.

The sudden cold snap in the capital, contrasting with autumnal temperatures last week, continues a recent trend of sharp swings in temperatures. Beijing experienced one of its warmest Octobers in decades in a year of extreme weather patterns.