Columbia police are investigating to see if there's a connection among a string of robberies when business employees have tried to make nighttime money deposits at area banks.

Four armed robbers have confronted workers going back to May 21st, with the latest incident happening Monday night.

Police spokeswoman Jennifer Timmons says in each case, one or more female employees were approached by a gunman between 9 and 11 p.m. either near the business or near a bank along Harbison Boulevard, Bush River Road or Garners Ferry Road.

“We know that they're happening around the time that employees are counting money or they know that they're going to drop money off at a local bank or the night deposit,” Timmons says.

“We don't really have good descriptions of the suspects at this point, simply because the men are disguised – either with a bandanna or some sort of mask on their faces, and wearing all black.”

Victims in two cases say the robber was a black male.    

Money was stolen in three of the four encounters.

Anyone with information on the incidents is asked to contact Columbia police or Crimestoppers.