A theft from a shop in St Paul's Bay was reported at 9.30pm on Monday, the police said.
The shop is based on Triq ix-Xitwa. Preliminary investigations found that a man armed with a knife entered the store and demanded money from a 52-year-old female employee.
The alleged thief escaped the scene with cash. Nobody was injured.
The police are currently searching for the culprit, and a Magisterial inquiry was launched.
Investigations are ongoing.