A Council Bluffs Post Office employee was robbed early Saturday morning on the back dock of the Post Office building on South Sixth Street.

According to a police department report, at about 12:35 a.m. the suspect came up behind the victim, stuck an unknown object in his back and demanded money.

"Don't do anything stupid, I know how to use this," the suspect told the victim, according to the report. The suspect then ran eastbound down the alley after getting between $13 and $20 in cash, according to the report.

The case was handed over the police department Criminal Investigation Division.