A deer hunter shot and killed five people and injured three others in northwestern Wisconsin following a dispute about a tree stand during the hunt's opening weekend, authorities said.

The 36-year-old alleged gunman, who lives in the Minneapolis area, was arrested Sunday afternoon, Sawyer County (search) sheriff's officials said. Jake Hodgkinson, a deputy at the county jail, identified the suspect as Chai Vang but would give no additional details.

The incident began when two hunters were returning to their rural cabin on private land in Sawyer County when they saw the suspect in one of their hunting platforms in a tree, County Chief Deputy Tim Zeigle said. A confrontation and shooting followed.

It's not known who shot first, Zeigle said.

Both hunters were wounded and one of them radioed to the cabin a quarter mile away. Other hunters responded and were shot. About 20 shots were fired, but it's unclear who shot them, he said.

The dead included four males — including a teenage boy — and a woman, Zeigle said. A father and son were among them, he said. Some of the victims were shot more than once.

All five, from the Rice Lake (search) area, were dead when officers arrived to the area in southwestern Sawyer County, he said. Authorities found two bodies near each other and the others were scattered over 100 yards.

"It's absolutely nuts. Why? Over sitting in a tree stand?" asked Zeigle.

Zeigle said the suspect was "chasing after them and killing them," with a SKS 7.62 caliber semiautomatic (search), a common hunting weapon. Wisconsin's statewide deer gun hunting season started Saturday and lasts for nine days.

Two young people who stayed in the cabin emerged safely after the shootings.

The suspect, who did not have a compass, got lost in the woods and two hunters, not knowing about the shootings, helped him find his way out, Zeigle said. When he emerged, a Department of Natural Resources officer recognized the deer license on his back, given to police by a victim, Zeigle said.

The man was out of bullets and was arrested, Zeigle said.

One of the injured hunters was in critical condition at St. Joseph's Hospital. Another was listed in serious condition and the third was in fair condition, both at Lakeview Medical Center.

Hunter Bill Wagner, 72, of Oshkosh, was about two miles away near Deer Lake with a party of about 20 other hunters. After they got word of the shooting, he and others went to round up the rest of the party. He said they heard sirens, planes and helicopters and noticed the surrounding roads blocked off.

"When you're hunting you don't expect somebody to try to shoot you and murder you," he said. "You have no idea who is coming up to you."

It took about three hours to round up the other hunters, who were up to four miles apart, Wagner said. "We're all old, dyed-in-wool hunters," he said. "We wouldn't go home because of this but we will keep it in our minds. We're not forgetting it."