Masked men terrorise service station worker with hammer

A female service station has been threatened with a hammer during a terrifying early morning robbery in Melbourne's north.

The young woman was working by herself on a Sunday morning shift when three men burst into the service station.

CCTV footage, shown on Channel 7, shows the men, wearing black balaclavas, arriving and smashing the store with a hammer and a tyre leaver.

The commotion attracts the attention of the employee who was out the back preparing breakfast.

She quickly surrenders and opens the cash register however one man continues to harass her with the hammer, smashing her mobile phone so she could not call for help.

A Victorian Police spokesperson told nine.com.au that an investigation into the attack continues.

It's understood the woman was treated at the scene by paramedics but was not injured.