Police say a Pennsylvania pizza shop customer armed with a gun shot and killed one robber and injured another as they tried to hold up the restaurant.

The shooting happened late Tuesday night at Porfirio's Pizza and Pasta in Levittown, about 25 miles northeast of Philadelphia.

Police say the customer shot both men after they allegedly pistol-whipped him.

One suspect was pronounced dead at the scene. The second was taken to a hospital. His condition was not immediately available.

Police say the customer and two pizza shop employees were the only people in the restaurant when the two armed suspects walked in.

Police say the customer's gun was properly registered, but they're unsure if he had a concealed carry permit.