Mississippi mass shooting: Man kills ex-wife and five others
The victims were killed at several locations, including a store and two homes, in Arkabutla, a community of fewer than 300 people.
Police have charged a 52-year-old local man with first-degree murder and held him at the county jail.
No motive for his attack has yet been identified.
The suspect is believed to have acted alone, said Mississippi Governor Tate Reeves.
The rampage began when the gunman entered a petrol station convenience store at around 11:00 local time (17:00 GMT) and shot a man to whom he had no apparent connection, Sheriff Brad Lance said.
He then went to a nearby home where he fatally shot his ex-wife and, according to CNN, struck but did not shoot her fiance.
Investigators say the gunman then drove to a home next to his own residence and fatally shot a man who may have been his stepfather, as well as an unnamed woman, the New York Times reports.
He then shot two people, one inside a car and one on the road, not far from his own home. The final two victims appear to have been construction workers on a job at the site, according to Sheriff Lance.
Deputies spotted the suspect inside a vehicle matching witness descriptions and were able to apprehend him near his home after a brief car chase.
"We don't have a lot of violent crime here. This is shocking," said Sheriff Lance. "I never dreamt that we would deal with something like that here."
He said the suspect had a shotgun and two handguns in his possession.
A primary and secondary school in nearby Coldwater were placed on lockdown during the incident, which unfolded 45 miles (72km) south of Memphis, in neighbouring Tennessee.
Ethan Cash, a 19-year-old local resident, told WREG-TV that he had seen the gun-toting suspect.
Mr Cash said he also checked the pulse of the victim who died inside his vehicle and drew his own pistol on an injured man nearby who turned out to be the victim's brother.