Hamilton police are asking for the public's assistance in an ongoing investigation into four robberies of women at ATM machines over the last two months.

The robberies took place on Nov. 15, Nov. 17, Nov. 24 and Dec. 4. Police believe the events are related.

Detectives are searching for a white male, in his 40s. The man is believed to be five-foot-seven with a heavy build, seen wearing dark clothing in security camera footage.

All incidents involve women who are being approached from behind while withdrawing cash before midnight at ATMs in the area of Upper James Street and Mohawk Road West.

The masked man is believed to be carrying a weapon, which he displays before robbing the women. In all cases, none of the women have reported any injuries.

Police are asking anyone with information about these robberies to contact Det. Jason Sorbara at 905-546-2377, or Detective Kevin Heyink at 905-546-2389, or to call Crime Stoppers at 1-800-222-8477.