TULSA, Oklahoma - Tulsa officers are looking at video evidence after men armed with a knife robbed a QuikTrip at 21st and Memorial early Monday morning.

Police said they are using surveillance video to try to catch the robbers - the clerk described them as both being 16 to 20 years old with T-shirts over their faces.

Around 1:30 a.m., police said the two robbers came in through the back door - one of them was holding a knife.  The person with the knife told the clerk to give him the money in the register, officers said.

The clerk gave up the money, and both people ran off to the north, toward the apartments behind the Sonic. If you know anything about who did this, you can always call Crime Stoppers at 918-596-COPS. Callers remain anonymous.