A woman was treated for a broken leg after being pushed to the ground by an angry customer in a shop.

The face mask dispute happened when Margot Kagan, 54, was using a fax machine inside a Staples store in Hackensack, New Jersey, US, on Wednesday afternoon.

Shocking CCTV footage captures the moment an agitated customer walking over to the fax machine area and starts yelling at her.

Margot, who is seen wearing a visor and holding a walking stick, steps back and raises her cane towards the woman.

But the angry shopper, who has her face mask pulled down below her mouth, snatches her cane away and pushes Margo to the floor, leaving her breaking the leg at the moment.

The angry shopper threw away Margot Kagan's walking stick and pushed her to the ground
The angry shopper threw away Margot Kagan's walking stick and pushed her to the ground

The scene unfolded after Margot, who had a liver transplant four months ago and was walking with a cane, told the woman to put her face mask on properly.

The suspect left the shop as Margot remained lying on the floor asking for help.

She was taken to a hospital where she was diagnosed with a fractured left leg.

According to NBC News, Captain Darrin DeWitt, a detective with the Hackensack Police Department, said: "The suspect became angry and yelled at the victim, who picked up her walking cane and pointed it directly at the suspect, coming within inches of the suspect's chest."

Margot left lying on the floor with a broken leg as the suspect fled the scene
Margot left lying on the floor with a broken leg as the suspect fled the scene

Police are now seeking to identify the suspect.

New Jersey governor Phil Murphy has said all residents must wear face coverings in stores.

Earlier this week, a couple were seen wearing face masks with swastikas in a Walmart supermarket.

They sparked fury with other customers and were later banned from entering any Walmart stores for a year after the video has gone viral.