Police are investigating the armed robbery of a pizza store in the Illawarra overnight.

About 9.30pm yesterday (Wednesday 3 July 2013), a man armed with a large kitchen knife and carrying a black shopping bag walked into the pizza store on the Princes Highway, Unanderra.

Once inside the premises, the man threatened the three teenage staff members working at the time – an 18-year-old male, a 17-year-old male and a 15-year-old female.

The man forced the employees to place money from the store’s cash registers into his black shopping bag.

He then left the store and was last seen running in a southerly direction along the Princes Highway.

Police were called to the scene and, after speaking to the teens, conducted a search for the armed man.

However, officers were unable to locate the man and would consequently like to hear from anyone who may be able to help them find him.

He is described as being approximately 180cm tall, with a heavy build and blue eyes.