PHILADELPHIA (CBS) — Police are investigating an armed robbery at a 7-Eleven in Northeast Philadelphia.

It happened around 2 a.m. Sunday at the 7-Eleven store along the 3300 block of Tyson Avenue in the Mayfair section of the city.

Police say a man with a gun walked into the store with a t-shirt over his face and demanded cash from the clerk.

The robber got away with hundreds of dollars in cash but no was injured.