ALAMEDA, Calif. (KRON) – Law enforcement says the level of illegal explosives this year is something they have never seen before.

KRON4 takes a closer look at those illegal fireworks, where they are coming from, and what can be done to keep them out.

Fireworks exploding in the skies in the East Bay on July 4th led to dangerous fiery embers falling onto homes, on top of roofs, or worse burning hands and fingers. Each and every one of these showy displays are illegal.

Sgt. Ray Kelly with the Alameda County Sheriff’s Department and Bomb Task Force says residents continue to set off fireworks days after the holiday, despite several high-profile busts this year.

For example, on Wednesday, the San Francisco Police Department released these photos showing the seizure of 69 pounds seized and a resident arrested.  

In San Mateo, a large cache was collected after an undercover bust.

In Walnut Creek, a fire ignited from fireworks and an explosion at a local apartment complex. Several hundred pounds were taken in and destroyed.  

It begs the question, where are these illegal works coming from and why can’t they be stopped.

Sgt. Kelly says battling the illegal sales proves incredibly challenging.