An armed woman has been interrupted allegedly robbing a Brisbane service station by an off-duty police officer.

Police say the 20-year-old threatened an attendant with two screwdrivers and demanded cash at the Sunnybank Hills service station on Sunday night.

The off-duty officer entered the store, realised what was happening and was able to disarm the woman with a cardboard store display and arrest her.

She will appear in Richlands Magistrates Court on Monday charged with attempted armed robbery and entering a premises to commit an indictable offence.

Extracted in full from Brisbane Times.