BEMIDJI, Minn. – A high school student went on a shooting rampage on an Indian reservation yesterday, killing his grandparents at their home and then seven people at his school, grinning and waving as he fired, authorities and witnesses said. The suspect apparently killed himself after exchanging gunfire with police.

It was the nation’s worst school shooting since the Columbine massacre in 1999.

One student said her classmates pleaded with the gunman to stop shooting.

“You could hear a girl saying, ‘No, Jeff, quit, quit. Leave me alone. What are you doing?'” student Sondra Hegstrom told the Pioneer of Bemidji, using the name of the suspected shooter.

Before the shootings at Red Lake High School, the suspect’s grandparents were shot in their home and died later. There was no immediate indication of the gunman’s motive.

In addition to the shooter, the death toll at the school included five students, a teacher, and a security guard, FBI spokesman Paul McCabe said in Minneapolis.

Fourteen to 15 other students were injured, Mr. McCabe said. Some were being cared for in Bemidji, about 20 miles south of Red Lake. Authorities closed roads to the reservation in far northern Minnesota while they investigated the shootings.

Ms. Hegstrom described the shooter grinning and waving at a student his gun was pointed at, 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.

Mr. McCabe declined to talk about a possible connection between the suspect and the couple killed at the home, but Red Lake Fire Director Roman Stately said they were the grandparents of the gunman. He identified the shooter’s grandfather as Daryl Lussier, a longtime officer with the Red Lake Police Department, and said Lussier’s guns may have been used in the shootings.

Mr. Stately said the shooter had two handguns and a shotgun.

“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,” Mr. Stately told Minneapolis TV station KARE.

Students and a teacher, Diane Schwanz, said the gunman tried to break down a door to get into her classroom. “I just got on the floor and called the cops,” Ms. Schwanz told the Pioneer. “I was still just half-believing it.”

Another student, Ashley Morrison, had taken refuge in Ms. Schwanz’s classroom. With the shooter banging on the door, she dialed her mother on her cell phone. Her mother, Wendy Morrison, said she could hear gunshots on the line. “‘Mom, he’s trying to get in here and I’m scared,'” Ms. Morrison told her mother.

All of the dead students were found in one room. One of them was a boy believed to be the shooter, Mr. McCabe said. He would not comment on reports that the boy shot himself and said it was too early to speculate on a motive.

Martha Thunder’s 15-year-old son, Cody, was being treated for a gunshot wound to the hip.

“He heard gunshots and the teacher said ‘No, that’s the janitor’s doing something,’ and the next thing he knew, the kid walked in there and pointed the gun right at him,” Ms. Thunder said.

The school was evacuated after the shootings and locked down for the investigation, Mr. McCabe said.

“It will probably take us throughout the night to really put the whole picture together,” he said.

It was the nation’s worst school shooting since two students at Columbine High School in Littleton, Colo., killed 12 students and a teacher and wounded 23 before killing themselves on April 20, 1999.

The rampage in Red Lake was the second fatal school shooting in Minnesota in 18 months. Two students were killed at Rocori High School in Cold Spring in September 2003. Student John Jason McLaughlin, who was 15 at the time, awaits trial in the case.

Red Lake High School, on the Red Lake Indian Reservation, has about 300 students, according to its Web site.

The reservation is about 240 miles north of the Twin Cities. It is home to the Red Lake Chippewa Tribe, one of the poorest in the state. According to the 2000 census, 5,162 people lived on the reservation, and all but 91 were Indians.