ARKABUTLA, Feb 17 (Reuters) - A gunman went on a rampage in a small Mississippi town on Friday, killing his ex-wife and five other people in three locations before sheriff's deputies arrested him, the county sheriff and witnesses said.

The bloodshed occurred in Arkabutla, a rural hamlet of less than 300 people in Tate County in northern Mississippi, about 40 miles (60 km) south of Memphis, Tennessee.

The gunman was identified as Richard Dale Crum, 51, and was charged with first-degree murder, Tate County Sheriff Brad Lance told reporters.

Investigators had yet to ascertain a motive but Lance said they would start by examining the suspect's relationship with his ex-wife.

Authorities first received a call about a shooting at a gas station convenience store, and before deputies arrived they received another call about a second shooting at a nearby home, Lance said.

One man was shot dead at the store. A woman, later determined to be Crum's ex-wife, was found dead at the home, Lance said.

Deputies tracked down the suspect in the driveway of another home and arrested him without a struggle, Lance said. That turned out to be Crum's home, and deputies found four more bodies there. Two were behind the home and two more in the roadway, one in a vehicle and the other on the road, Lance said.

The suspect may have had a family connection with the victims behind the house. The two men on the roadway appeared to have been workers on a job at the site, Lance said.

"We don't have a lot of violent crime here. This is shocking," Lance said. "I never dreamt that we would deal with something like that here."

Deputies recovered a shotgun and two handguns from the suspect, Lance said.

One man who witnessed some of the events at the store said he pulled out his pistol and considered firing at the suspect, who was armed with a shotgun, but decided to hold his fire.

Instead, witness Ethan Cash told Reuters, he tended to a man who was shot inside his car outside the store and found he had no pulse and was unresponsive.

Cash, 18, said he then drew his pistol on another man, who turned out to be the victim's brother, who was injured.

"He said, 'Man, they just shot my brother,'" Cash said. "And I'm like, 'Man, I'm so sorry. Let's make sure everyone is OK.'"

Cash said he spotted the suspect and considered opening fire.

"I was going to start shooting at the guy as he was pulling off but I didn't know who exactly it was and I didn't want to hurt anybody, so I kind of let the officers do that. It's their job, anyways," Cash said.

Cash predicted the shootings would leave a deep impact on the small, where most people know each other and violence is rare.

"It's definitely confusing when it happens," Cash said, "especially when you hear six, seven people are murdered and no one knows why."