Los Angeles firefighters responded to the scene in the 13700 block of Glenoaks Boulevard about 4:30 a.m. Sunday and found multiple structures ablaze, authorities said.

Their efforts to knock down the fire were hampered by the presence of ammunition in one of the homes, according to L.A. Fire Department Capt. Erik Scott. The blaze’s heat then set off the ammunition, leaving the impression that a gun was being fired, he said.

Once the fire was under control, firefighters found human remains in one of the structures as well as multiple guns in one of the three houses on the property.

“I saw at least two, what appeared to be, automatic weapons — a rife, ammunition lined up,” Scott told KTLA-TV. “That obviously concerns us — why is that out?”

The cause of the fire has not been determined.

Authorities had not yet released any information about the identity of the deceased person. Dogs were being used to search for more human remains and Los Angeles police were assisting in the investigation.

Both departments Sunday morning were still on the scene.