A young woman in Taiwan narrowly escaped death by slashing in broad daylight on Sunday after four passers-by stepped in to beat back her alleged attacker.

A man surnamed Hsu and his two adult sons had stopped at a red light in their car when they saw a woman being attacked by a man with a box cutter who had followed her into an alley. The incident happened at noon in Taitung, a coastal city in south-east Taiwan.

Mr Hsu told reporters later that instincts told him that “if I do not save her, she will be killed”.

He grabbed a soup ladle from the car, while his sons armed themselves with a table fan from a nearby betel-nut stall and the woman’s hardcase luggage, and they distracted the man from the woman, reported United Daily News.

Closed-circuit television footage shows the alleged attacker, known by his surname Chang – in a blue long-sleeved top – holding the cutter and being surrounded by the three men in a stand-off near a pavement under the hot sun.

Chang is disarmed when the elder Hsu moves in to strike his weapon-holding hand from behind with the ladle.

Along with a fourth passer-by holding what appears to be a metal rod, the trio subdue Chang and pin him face down on the road.

In another video, the 50-year-old Chang can be heard yelling: “Don’t press me down, the ground is very hot.”

The 26-year-old victim, identified as Ms Chiang, suffered slashes in her ears, neck, left hand and left thigh.

Taitung police said in a press conference on Sunday the suspect had been arrested and Ms Chiang was in stable condition.

Police said the suspect had a second box cutter in his backpack and is being investigated for attempted murder.

His motive and relationship with the victim remains unclear, but local media reported that they do not know each other.