Man, 72, threatened with knife in robbery

A 72-year-old man has been threatened with a knife during a daylight armed robbery in Sydney's southwest.

The man was working at the counter of a shop in Padstow, when another man entered the shop, threatened him with a knife and demanded cash at about 3.40pm on Thursday, police said.

The robber walked around the counter and took cash from the register before running off.

The attendant was not injured during the incident.