Just three weeks after a masked man armed with a knife robbed a Riverside convenience store of $250, police have reported that the store has been robbed again.

Riverside police say a man who implied he was carrying a handgun walked into 7-Eleven, 2600 Harlem Ave., just prior to 9:30 p.m. on Tuesday and robbed the clerk of an undisclosed amount of cash.

According to Police Chief Thomas Weitzel, a man wearing black clothing and something white covering his face walked into the store and demanded money from the register. The man didn’t display a handgun, said police, but he appeared to point a handgun, which was under his shirt, at the clerk. Police also said the man appeared to be wearing socks over his hands.

Nobody was hurt during the incident.

After taking money from the cash drawer, the man fled behind the store into a wooded area along the Canadian National Railroad tracks. A police K-9 unit called in from Berwyn found a white T-shirt along the tracks. Police believe the T-shirt may have been used to cover the robber’s face.

Tuesday’s incident is the fourth time the 7-Eleven store has been robbed since December 2009, when two men held up the clerk and stole $300.

In October 2010, a man wearing a “Scream” style Halloween mask and brandishing a knife robbed the clerk of $250. On Sept. 29 of this year, a man wearing a bandanna over his face and wielding a large butcher knife robbed the clerk of $250.