Christopher Lee and Shankar Vedantam, Washington Post Staff Writers, report:

Ten people were killed and more than a dozen were wounded yesterday by a gunman who opened fire at a high school and a private home on an isolated Indian reservation in northern Minnesota and engaged in a brief gunfight with police before killing himself, the FBI said.

The gunman killed his grandfather and a woman at his house, local officials said. They said he then traveled to the high school in Red Lake, a town of a few thousand on the southern shore of an inland lake, where witnesses said he charged into the school waving his gun and grinning as he shot down students, teachers and a school security guard.

The name of the student was not disclosed by officials, but the Associated Press reported that several students said he was Jeff Weise. It was not immediately clear if he was a student at the school.

“At this time, we do believe the shooter acted alone,” FBI spokesman Paul McCabe said in a telephone interview last night. It was the nation’s deadliest school shooting since two students at Columbine High School in Littleton, Colo., killed 13 people and wounded 23 others before killing themselves on April 20, 1999.

The shooter entered Red Lake High School, which has about 300 students, in the middle of the afternoon. The security guard, who was at the entrance, was the first person shot, McCabe said.

Student Sondra Hegstrom described the gunman waving at a student while pointing his gun and then swiveling to shoot someone else. “I looked him in the eye and ran in the room, and that’s when I hid,” she told the Pioneer newspaper of Bemidji, Minn., according to the AP. “You could hear a girl saying, ‘No, Jeff, quit, quit. Leave me alone. What are you doing?’ ”

All the dead at the school were found in the same room, McCabe said. They included a school security guard, a female teacher and a number of students. Fourteen other students were injured, but the extent of their injuries was not known last night, and McCabe declined to comment on where the injured were found.

“After he shot a security guard, he walked down the hallway shooting and went into a classroom, where he shot a teacher and more students,” Red Lake Fire Director Roman Stately told Minneapolis television station KARE.

Students and a teacher at the scene, Diane Schwanz, said the shooter tried to break down a door to get into a room where some students were hiding. “I just got on the floor and called the cops,” Schwanz told the Pioneer newspaper. “I was still just half-believing it. I just got down on the floor and [said], ‘Kids, down on the ground, under the benches!’ ” She said she called police on her cell phone.

Ashley Morrison, another student, took refuge in a classroom. With the shooter banging on the door, she dialed her mother on her cell phone, AP reported. Her mother, Wendy Morrison, said she could hear gunshots on the line.

“Mom, he’s trying to get in here and I’m scared,” Ashley Morrison told her mother.

“He randomly walked up and down the halls shooting,” said Eleanor Annette, whose daughter Kathleen Annette is the head of the Indian health service in Red Lake. “They are coming into the Bemidji hospital by the planeloads. There is an Indian hospital, but they can’t accommodate them. They are taking them from the reservation to Bemidji and then to Fargo.”

Four tribal police officers arrived as the youth was shooting and exchanged gunfire with him, McCabe said. The shooter retreated into a classroom, where he was later found dead. Police told AP that he had shot himself.

After the shooting, parents raced to the school to check on their children. Authorities evacuated the school and locked down the campus as law enforcement officers began an investigation that includes help from the Red Lake tribal police, the Minnesota state police, the Beltrami County Sheriff’s Office and the federal Bureau of Indian Affairs. An FBI evidence-recovery team was sent to the scene. The FBI field office is in Minneapolis, but five agents are regularly stationed in the Red Lake area and are getting support from the field office, McCabe said.

“The investigation will be ongoing throughout the night,” he said.

Stately said the gunman killed his grandfather, whom the fire official identified as Daryl Lussier, a longtime officer with the Red Lake Police Department. He said that the shooter had two handguns and a shotgun and that they may have been Lussier’s guns, according to AP.

The killings yesterday were the second major school shooting in Minnesota in recent years. In September 2003, two students were shot at Rocori High School in Cold Spring in central Minnesota. John Jason McLaughlin, a student who was 15 at the time of the shooting, awaits trial in the case.

Poverty on the Red Lake Reservation stood at 40 percent, the highest of any reservation in Minnesota, according to the 2000 U.S. census, the Minneapolis Star Tribune reported last year.

The reservation has seen violence before.

In January 2004, locals raked police buildings with gunfire, prompting a crackdown by the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives. Three years ago, the Justice Department launched a major crackdown on drugs and guns on the reservation, which has a population of about 9,000 people. Officials found evidence of executions, drive-by shootings and ritualistic violence.

Local residents blamed poverty, discrimination, and endless cycles of drug and alcohol abuse. They said gangs often offered the only refuge for aimless youngsters.

As early as 1979, FBI agents had to be sent into the reservation to investigate widespread rioting and looting triggered by internal politics and dissatisfaction with the management style of the BIA. Several dozen Indians stormed the jails, locked up police officers and damaged property.

Red Lake is a closed reservation, meaning it is owned entirely by tribes, in this case the Chippewa Indians.

The shooting left the town reeling.

“You just can’t imagine it would happen,” said Karla Pankow, manager of a local grocery store, the Trading Post. “There’s a lot of hurt people and a lot of devastated people because it’s a small community and everybody knows everybody.”

Research editor Lucy Shackelford contributed to this report.