Teens with a gun hold up NSW servo

A woman has been threatened with a handgun by three teenagers who held up a service station on the NSW Central Coast and fled with cash.

Police say that shortly after 11pm on Sunday a teenage male knocked on the glass doors of the Wyong business and the sole staff member working there let him in.

As the doors opened, two other teens, one of them armed with a handgun, ran into the store.

The trio, who were all wearing hooded jumpers, threatened the 47-year-old woman and forced her to hand over cash, before they fled on foot.