Investigators in the East Bay city of Concord suspect foul play in the death of a person whose remains were found in a house that was likely set on fire Thursday evening.

The blaze started just before 6 p.m. on the 3500 block of Euclid Avenue, as KTVU reports, and firefighters found one person dead on the scene. Investigators with the Contra Costa County Fire Protection District quickly determined that "the fire was intentionally set in multiple locations throughout the house," as they reported on Twitter.

Concord police were called to the scene upon the discovery of the body, they told KTVU. They were not releasing any details, and only said on Twitter that an investigation was underway.

A police officer on the scene told KTVU that there was something "found inside the house that was concerning."

Neighbors expressed surprise about the size of the blaze, speaking to KTVU. And one neighbor reported hearing "five to seven explosions" that she mistook for gunfire.