A police officer has been charged with six counts of sexual assault, on the same day a sergeant was charged over an alleged assault while on duty.

Professional Standards Command charged the policeman from the north-west metro region with six counts of sexual assault, Victoria Police said on Tuesday.

Credit:Leanne Pickett

The region covers Broadmeadows, Carlton, Carlton, Collingwood, Greensborough, Heidelberg, Reservoir, Essendon, Footscray, Sunshine and Werribee.

He will appear in court at a later date.