Law enforcement officials told ABC News that what's being described as a substantial quantity of the high explosive TATP was found at the home.
Police say what led them to the house was a reported hand injury at a local hospital. The suspect, 23-year-old Benjamin Kuzelka, told authorities his hand was injured in an accidental shooting. But authorities became suspicious because his injuries were inconsistent with a gunshot wound.
Sgt. Dennis Gutierrez of the Riverside County Sheriff's Department said investigators searched the home, where they found explosives and a sophisticated marijuana-growing facility. They also found evidence that the home had been used as a state-licensed child care facility as recently as the day before.
Benjamin has been arrested, along with his brother, 21-year-old Grey Kuzelka, and mother, 55-year-old Rebecca Kuzelka, who owns the property and runs the day care.
All three are being booked on suspicion of manufacturing illegal explosives, illegal growing of marijuana and child endangerment.
An extensive, multi-agency investigation -- including the Riverside County Sheriff's Department, the FBI and the ATF -- is under way.
The bomb squad detonated three devices found inside the home early Thursday morning.
"I believe at 6:10 we heard a big explosion and we came running out of the house and we didn't know what was going on," said neighbor Pam Espinoza. "It was really scary. It set off a bunch of car alarms and stuff like that."
"The boom was so loud it felt like Lake Elsinore was going down under," said resident Maryanne Lomonico.
No children were inside the home at the time of the blast, but authorities say kids were on the property when the illegal activity was going on.
Neighbors were shocked to hear about what was allegedly happening in their community.
"They've been a little strange but, I mean, I thought it was a meth lab, not what it is. You know, the marijuana and the explosives, I would never have thought that," said April Fashbaugh, who lives across the street from the suspects.
"When I heard the type of it was, like, how severe it could have been, it could have been really worse, I can't believe it. I'm, like, ready to move out of this place," said neighbor Nicole Kirkpatrick.
Friends said the 23-year-old suspect was pretty normal and liked to work on cars and motor bikes.
Neo Nazi and anarchist-type literature were allegedly found in the home, but police have not confirmed this information.
The FBI said there was no immediate indication that the case was linked to any terrorist investigation or any threat to public safety.
TATP explosives were used in the 2005 London bombings and suspected in the current Zazi alleged terrorism case.
Anyone with information concerning this incident is urged to call the Lake Elsinore Station at (951) 245-3300.
Eyewitness News reporters Bob Banfield and Rob McMillan contributed to this report.