An evening rush-hour accident on the Beijing metro left 102 people with fractures after a rear-end collision on an above-ground section of tracks, state media reported Friday.

The Chinese capital -- where such incidents are rare -- has been hit by snowstorms in recent days, affecting operating conditions and resulting in transport delays across the city.

The accident occurred at 6:57 pm (1057 GMT) Thursday, when the last two cars of a metro train separated from the carriages in front of them, authorities initially reported.

As of about 11:00 pm, "a total of 515 people were sent to the hospital for examination, of which 102 suffered fractures", state-run broadcaster CCTV reported Friday.

By 6:00 am Friday (2200 GMT Thursday), 423 people had been released from the hospital, said CCTV, adding that 67 others were still receiving treatment while 25 people were under observation.

No deaths had been recorded, CCTV said.

A preliminary investigation into the incident found the snowy weather had caused slippery tracks and a "signal degradation", resulting in a rear-end collision, the report stated.

Social media users reported seeing passengers fall to the ground, with some complaining of back pain.

Media images showed riders on the floor and partial lighting outages, while 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 rider, while stranded passengers made their way through deep snow to leave the scene.

The train was travelling on an above-ground section of track when the accident happened near Xi'erqi Station as it headed toward Changping district in the northern part of the city.

"We sincerely apologize for the accident that occurred this evening," Beijing Subway, the train's operator, said on Weibo.

"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," they added.