A homicide investigation is underway in Montclair after three people were found shot to death inside a home.

Around 9 p.m. Monday, San Bernardino County Sheriff’s Department deputies responded to a call in the 4800 block of Ramona Place, officials said.

The deputies entered the home and found three adults dead from gunshot wounds.

The three people have been identified as Sonia Ramirez, 68, George Ramirez, 66, and David Ramirez, 43. All three were residents of Montclair, officials said.

The circumstances behind the victims’ deaths remained unclear Tuesday afternoon. Investigators said there is nothing to indicate the incident was a murder-suicide, but no information about a possible suspect or suspects have been announced.

Neighbors said they heard what sounded like fireworks going off Monday night in the otherwise quiet and safe neighborhood.

Investigators remained at the scene Tuesday morning, aerial video from Sky5 showed.

A body was removed from the home as detectives searched a neighboring backyard and police dogs sniffed for clues in the area.

“One of the guys who lived there is, I believe, gang-related,” said Chris Sanchez, a neighbor. “So, it’s shocking that it happened in this neighborhood, but it’s kind of not out of the question that would happen to somebody.”

Authorities have not commented on whether or not the slayings were at all related to any gang activity.

Neighbors tell KTLA they’re concerned as the suspect remains at large.

The area surrounding the home remained cordoned off as detectives continued investigating the scene.