"There were no reported injuries or substantial property damage resulting from the detonation of the device," Sgt. Dixon said in a statement.
A 17-year-old juvenile, a resident of unincorporated Menlo Park, admitted to detonating the device in the grass field, police said. The juvenile, whose name was not released, was charged with possession and detonation of an explosive device.
Police and the San Mateo County Sheriff's Office bomb squad searched the juvenile's home and found no other explosive devices or materials used to make such devices, police said. The San Mateo County Crime Laboratory helped gather evidence at the scene.
Police ask anyone with information about this incident to call Officer Swanson at 330-6300 or the anonymous tip line, 330-6395.