Knife pulled in Brisbane servo robbery

A man is on the run after threatening a convenience store worker with a knife in a robbery in Brisbane's north.

The employee, a 64-year-old man, handed over cash and cigarettes after the robber entered the Wavell Heights store and produced the knife at about 6:35pm on Sunday, police say.

The man fled the store on foot and it's believed he ran up to a car, being driven by someone else, to get away.