Four children were killed and three other people were injured when a house fire broke out early Wednesday in a small town in southwest Oregon, officials said.

Douglas County Deputy Dwes Hutson said the children ranged in age from 4 to 13. Two adults and a 13-year-old boy survived and suffered serious injuries in the fire.

Thirty-nine-year-old James Keith Howell, 38-year-old Tabitha Annette Howell and 13-year-old Andrew Hall-Young were transported to Legacy Emanuel Medical Center in Portland, Fox 12 Oregon reported.

Killed in the blaze were 4-year-old Gwendolyn Howell, 7-year-old Haley Maher, 10-year-old Isaiah Young and 13-year-old Nicholas Lowe, who was a foster child, according to Hutson.

Hutson said at a news conference the blaze started around 2 a.m. local time, and when firefighters arrived, the home the completely engulfed in flames.

“There were several people that were seriously injured that were transported, and the injured are very seriously injured,” Hutson said.

Riddle is located about 200 miles south of Portland in a rural and heavily forested county.

The Oregon State Fire Marshal's Office and the Oregon State Police Arson Investigation Unit are assisting the Douglas County Sheriff's Office in the investigation.

So far, the cause of the fire does not appear to be suspicious, according to Hutson.

Read more at KPTV.com.

The Associated Press contributed to this report.