Police say 19 razor blades have been found at a San Diego park where two boys were treated for cuts on their feet.

Officer Dino Delimitros says a mother reported her two barefoot sons, ages 7 and 15, stepped on razor blades Wednesday evening at Bonita Cove Park in Mission Bay.

U-T San Diego reports officers using metal detectors found 19 blades near one of two playgrounds at the park.

The newspaper says razor blades were also found in the area last summer.

In August, a woman cut her foot while walking through grass near one of the playgrounds. Eight blades were found in the area.

Across the street several weeks later, about 20 razor blades were found in a park area across the street. No one was injured.