REDDING, Calif. -

Investigators spent Friday at the scene of an explosion that blew a man's hand almost completely off.

The initial blast happened at about 4:30 p.m. Thursday at a home on Chaparral Drive.

Shasta County Sheriff’s Lieutenant Tom Campbell explained how bomb squad crews are taking their time and using caution while they investigate.

"Obviously we're going very slow because of the delicate nature of any kind of explosive devise or chemicals. We're trying to do our best to keep our people safe and go slow," said Lt. Campbell.

Emergency crews quickly responded following reports that a man had suffered blast injuries after working with some sort of rocket fuel that ignited.

"We've found nothing so far to indicate that this is anything more than a hobby. There's nothing that indicates this is a terrorist act as of right now. But again, the investigation is still continuing," explained Campbell.

The bomb squad's robot was deployed multiple times to examine materials inside the home.

When asked if law enforcement had been out to the home where the blast occurred under similar circumstances, Campbell said, “Not that I am aware of. We've had some calls for service in the area of sounds of explosions in the past, but I don't know if it’s specifically at this residence," said Campbell.

Stay with KRCR News Channel 7 for new details on this developing story.