MINNEAPOLIS (WCCO) — The Pine County Sheriff’s Office is asking for the public’s help after they say two men wearing ski masks attacked and robbed a bar employee in Willow River on Independence Day.

On July 4 at 1:22 a.m., the Sheriff’s Office said two men entered the Corral Bar wearing black ski masks. At least one was armed with a handgun, and they held a lone female employee at gunpoint, police said.

They demanded the woman, who was in her mid-60s, to open the safe containing the day’s earnings.

When the employee could not open the safe, she was pistol-whipped in the head by the armed man, according to the Sheriff’s Office. The men then robbed the employee and fled the business.

The victim was taken by ambulance to Mercy Hospital, where she received staples for a laceration to her head. She has since been released.

There was a surveillance camera in the bar, but police said the images are of such poor quality, it’s not helping much in their investigation.

The sheriff’s office does claim to have “persons of interest” they were led to by witnesses and other bar employees. Investigators are working to interview them.

Police said there have not been other similar robberies in the area lately.

Anyone with information on this incident is urged to call the Pine County Sheriff’s Office at 320-629-8380.