Four people were killed at two separate residences in the small farming town of Laurel, Nebraska, on Thursday in what police are investigating as crimes, authorities said.
Local police and fire departments responded to the first residence after a witness called to report what was described as an explosion followed by fire and found one victim. A short time later, a second fire was reported at a home several blocks away, where three more victims were found.
State Patrol later said investigators suspected gunfire played a part in both crime scenes.
The gunshots were suspected to have started at around the same time, the State Patrol said in a statement, adding the second fire was not visible outside the home for hours.
A silver sedan was spotted leaving Laurel - a small farming community located about 40 miles (64 km) west of Sioux City, Iowa - much later after the second fire than previously thought, the State Patrol said.
"Foul play is suspected in these deaths," Colonel John Bolduc of the Nebraska State Patrol said at a news briefing.
"We would describe that individual as a person of interest," Nebraska State Patrol spokesman Cody Thomas said in a text message, referring to the driver of the silver sedan.
This is a developing story.