MINNEAPOLIS -- Police are are warning residents near downtown Minneapolis about a masked gunman barging into homes.

The warning was sent in a letter last week to residents of Heritage Park. Police confirm four separate home invasion burglaries in the area in the past two months, three of which were in the last two weeks.

According to authorities, the suspect rings the doorbell and when the homeowner opens the door, the masked suspect barges in, brandishing a gun and demanding money.

Police say the suspect has made off with cash, credit cards and a phone. No one has been injured during the incidents.

No arrests have been made. Police say they are conducting interviews and following up on leads.