ALAMEDA, Calif. (AP) — A parcel mailed last week to the home of a Northern California police officer exploded, injuring a woman who opened it, and federal investigators were trying to determine if the case is linked to an incident in October when a package sent to another residence detonated, officials said Tuesday.

Postal Inspector Jeff Fitch said a package delivered to a house in Alameda detonated Friday. The intended recipient was a city police officer but a woman opened it and had non-life threatening injuries, sheriff's Sgt. Ray Kelly told the San Francisco Chronicle.

He would not release any other details.

Federal officials are also investigating a package that exploded Oct. 19 after it was delivered to an East Palo Alto home, Fitch said.

Evidence collected from the home was sent to the U.S. Postal Inspection Service lab in Virginia to be analyzed along with the evidence from the Alameda blast.

Fitch said it has not been determined if the cases are connected.

"It's early in the investigation to make any connections like that," he said.

East Palo Alto resident Veronica Maldonado told KGO-TV her father was injured the parcel exploded as he opened it.

The box was a foot long and was labeled as if it came from a local jewelry store, she said.

"Luckily it exploded in the opposite direction from where he was standing so he wasn't hurt very much, other than his hand a little bit — the one that was holding the box," she said.