A man shocked onlookers when he pushed a woman onto train tracks at a station in Hong Kong, causing her to fall and hit her head.

The harrowing CCTV footage shows him strolling past a woman in a hi-viz vest before knocking her onto the tracks.

After falling, she looks up at her attacker.

The 59-year-old unnamed cleaner was shoved onto the rails by a man who then slowly walks away from the scene.

According to the South China Morning Post, she had been on platform No 5 at the Yuen Long terminal for the Light Rail’s 761P route at about 10.30am.

She waved to an acquaintance before being shoved onto the tracks.

No train was passing at the time, but the terrifying possibility clearly resonated with social media users, who have shared the video thousands of times.

According to the South China Morning Post, the man was arrested on suspicion of assault.

A spokeswoman told the newspaper: “The woman suffered injuries to her jaw and was sent to Pok Oi Hospital for treatment.”

It is understood the alleged assailant has a Hong Kong identity card. Officers are now searching for a motive.