San Jose police said today that the arrest of a man on Thursday for allegedly having explosive materials at a home in the city is connected to an investigation into attacks on PG&E transformers in the area in recent months.

Peter Karasav, 35, was arrested in the 600 block of Potomac Court morning of March 2 and investigators said they found explosive materials and possible narcotics activity at a home there.

San Jose Police Sgt. Christian Camarillo told Bay City News:  "there is so much material in there that we've had to call in some federal resources to assist us," including the FBI.

Police said Friday that the investigation began following an explosion early on the morning of Dec. 8 that damaged a transformer in the 5000 block of Thornwood Drive.

A second transformer was reported damaged in an explosion early on the morning of Jan. 5 in the 6000 block of Snell Avenue.

More information about the investigation was not immediately available.

PG&E issued a statement about the case Friday afternoon.

“PG&E takes seriously the protection of critical infrastructure, and we appreciate the responsive action of the SJPD," the utility said.

Here is the Twitter thread about this case, posted by the San Jose Police Department Office of Media Relations:

March 1

• Detectives and Special Operations personnel are currently in the 600 block of Potomac Dr conducting an operation. One suspect is in custody for possession of explosive material. No public safety threat at this time.
• We will be at this scene for the next 24-48 hours. There is a substantial amount of evidence that needs to be collected. We will keep the updates coming as info becomes available.
• We are also investigating possible narcotics activity at this location. This is an ongoing investigation. Additional details will be shared as they become available as well as the suspect’s identification.

March 2

• San Jose police today announced the arrest of a suspect for possessing explosives at a residence in the 600 block of Potomac Court. Police said they also are investigating possible narcotics activity at the same location.
• Update: This investigation began with two separate incidents involving explosive devices between December and January.
• On Jan. 5,  around 1:00 pm officers responded to the 6000 block of Snell Ave. on a report of a damaged transformer. A PG&E employee stated that an explosion occurred the night before around 2:00 am.
• The PG&E employee also stated that a similar incident occurred on Dec. 8, 2022 around 4:00 am at the 5000 block of Thornwood Dr. in which an explosion caused damage to a transformer.

San Jose Inside contributed to this report.