Police said two female employees were inside a pharmacy on Darby Street around 7.45pm when an unknown man entered the store through a rear entrance.

The man then approached the counter and threatened one of the attendants with a knife before demanding medication, police said.

The other employee activated an alarm and the man fled the store empty handed through the rear entrance onto Railway Street.

Officers from Newcastle City Police District conducted patrols of the area however were unable to locate the man.

He is described as being about 180cm tall, with a thin build, dark clothing and a dark face covering.

Police are urging anyone who may have CCTV or dashcam vision from the area around this time or who may have noticed anything to contact Newcastle Police on 4929 0999 or to contact Crime Stoppers on 1800 333 000 or online.

While you're with us, did you know the Newcastle Herald offers breaking news alerts, daily email newsletters and more? Keep up to date with all the local news - sign up here.