WATCH: Shocking video shows railway worker shoved onto tracks without warning

A man has been arrested after he allegedly pushed a railway worker onto the tracks from behind in a sickening attack.

CCTV footage shows the 59-year-old woman walking along the platform in Hong Kong before she comes to a stop.

A man is then seen walking behind her and pushes her from behind, forcing her to fall face first onto the railway tracks.

The unsuspecting attack happens so quickly she can't put her arms up to shield her fall.

Footage shows the alleged attacker continues to walk along the platform calmly, and without looking back.

CCTV shows the man pushing the woman onto the tracks. Source: Facebook

The cleaner is seen lying motionless on the tracks.

The 56-year-old alleged attacker was arrested near the railway station on suspicion of assault, the South China Morning Post reports.

No trains were approaching at the time of the incident and the woman was rescued from the tracks.

The woman landed head first. Source: Facebook

“The woman suffered injuries to her jaw and was sent to Pok Oi Hospital for treatment,” a police spokeswoman told the Post.

Officers from the Yuen Long criminal investigation division are looking into the motive.