Media playback is unsupported on your device Media caption The video appears to show a man drag a woman to the floor

Footage that appears to show a woman being assaulted in a Beijing hotel has sparked a massive debate in China.

CCTV footage shows a woman being grabbed and dragged across a hotel corridor, in full view of bystanders.

Although the incident is still being investigated, it has prompted millions of posts on social media, which have been viewed over two billion times.

China has seen several incidents in recent years where bystanders have refused to help those in need.

Beijing police say they are investigating the incident, and the hotel's parent company has apologised.

The video was uploaded on Sina Weibo, China's version of Twitter, earlier this week, by a woman identified by her online username, "Wanwan".

Image copyright @弯弯_2016 Image caption "Wanwan" said she was choked and grabbed by the man

Image copyright @弯弯_2016 Image caption The footage showed her being dragged across the corridor

"Wanwan" said the man had approached her in the hotel corridor of Yitel Hotel and asked her which room she was in.

"I said 'What do you want? I don't know you' and then he started to drag me away. He clutched my neck and face so I couldn't breathe.

"When I tried to run downstairs, he grabbed me by the hair and dragged me towards the stairway."

A staff member had seen them but assumed it was a couple's quarrel and did not intervene, she said.

Image copyright @弯弯_2016 Image caption Eventually, a bystander appeared to take her to safety

In the footage, the staff member and other hotel guests can be seen watching the scuffle, but most did not get involved.

Eventually, a bystander appears to help her leave the scene.

Homeinns, the parent company of Yitel Hotel, has issued an apology to "Wanwan" and the public.

The incident showed "insufficient security management and customer service", Homeinns said in a statement.

The video has become one of the most-discussed topics on Chinese social media, and prompted debate over why many are reluctant to help strangers.

The hashtag "Girl attacked at Yitel" hotel was used more than two million times, and viewed more than two billion times.

Some circulated a video campaign called "#WhoWillYouHelp", produced by the Ontario government last year to combat sexual harassment.

Image copyright @姗姐有话说/ Onatario Government Image caption This user shared the Ontario film, and wrote: "When you do nothing, you're helping him! Don't be a numb bystander, help others, please don't stay silent."

Others expressed their anger at the hotel, or shared tips on self-defence for women.

Image copyright @樊君和 Image caption This user wrote: "Although I know I don't have much power, this is how I feel! I'm so disappointed at Home Inns! I've decided never to stay in their hotels again!"

Image copyright @交通安全蜀黍 Image caption Users also shared self-defence tips for women

Weibo user Winston urged people to stop turning a blind eye.

"If people stop being indifferent and calling it as a 'domestic incident' when husbands/boyfriends beat, drag or abuse their wives/girlfriends in public, wouldn't there be fewer of these dangerous situations?"

There have been several high-profile cases in recent years where bystanders have refused to help people in need.

In one case in 2011, a two-year-old girl was knocked over in a hit-and-run accident - and 18 people passed the seriously-injured girl before someone came to her rescue. She later died from her injuries.

And in 2015, a 57-year-old-man staggered and collapsed at the corner of a road. Four cars and 23 people passed by, but no one helped him, and he later died in hospital.

Many are reluctant to intervene because there have been several incidents where injured people have subsequently blamed those who came to their aid for causing the injuries - and sued them.