Authorities are investigating after reports of an explosion Wednesday morning at a residence in an unincorporated area of Tustin.
At the scene, a bomb squad unit was stationed outside of a residential building on busy Newport Avenue.
Authorities were called in after someone discovered an exploded piece of a terra cotta vase in their backyard, according to Lt. Patrick Rich of the Orange County Sheriff's Department.
Around 9 a.m., bomb squad authorities responded to the scene, where they spoke with a resident who allowed them to enter the building.
Once inside, investigators reportedly found a pipe bomb inside the resident's living room. At that point, more units were called in and the area was blocked off.
"That initial explosion, it is undetermined at this point what caused it but there is, what we believe, another device inside the residence at this point," Rich said.
That resident was taken into police custody. Authorities said the 38-year-old suspect may be behind several other explosions reported in the area in recent weeks. They said there have been three or four other incidents, including a mailbox blown up and a fence blown up.
The reported explosion triggered evacuations and street closures while bomb investigators eventually disabled the device.
The investigation is ongoing.