Horror as Good Samaritan dies after being allegedly stabbed to death by an armed robber he confronted at a service station

A Good Samaritan has died after allegedly being stabbed to death when he confronted an armed robber at a service station.

NSW Police said a 24-year-old man tried to hold up the petrol station in suburban Newcastle, north of Sydney just after 8pm on Saturday.

The man allegedly threatened a worker with a knife before running away empty handed, heading south down Sandgate Road in Shortland.

The alleged knifeman is then accused of approaching the entrance of a second service station where he was confronted by a 54-year-old man who was also entering the store.

Paramedics tried to save the 54-year-old Good Samaritan at the scene after he was allegedly stabbed to death by an armed robber but the man did not survive

The scene outside one of the two Sandgate Road service stations in Shortland, NSW, on Saturday night

The Good Samaritan was allegedly stabbed in the stomach by the younger man, 24, during the confrontation, police said on Saturday.

The man was treated by paramedics at the scene but tragically died of his injuries. 

Police said initial inquiries suggested the two men were strangers. 

The younger man fled down Sandgate Road into a house.

The 24-year-old man ran south down Sandgate Road from one service station which he tried to rob, before allegedly stabbing a 54-year-old man to death, police said on Saturday

Police set up crime scenes outside the two service stations on Saturday night after the fatal alleged stabbing. Pictured: emergency services at the scene

Police later arrested the 24-year-old from the house after receiving information.

As of Saturday night he was being held for questioning at Newcastle Police Station.

Police have set up crime scenes at both service stations and the house where the younger man was arrested.

The investigation continues. 

Police have asked anyone with information to call Crime Stoppers on 1800 333 000.