A high school student shot dead nine people and then killed himself at Minnesota's Red Lake Indian Reservation in the worst school shooting since the 1999 Columbine massacre, authorities said.
   
Among the dead at Red Lake High School were a male security guard, a female teacher, and at least six students including the gunman, the FBI said. At least a dozen others were wounded in the carnage.
   
Before arriving at the school, the gunman shot dead his grandfather, identified as veteran tribal police officer Daryl "Dash" Lussier, and Lussier's girlfriend at their home in Red Lake village.
   
"We believe the shooter was acting alone," FBI agent Paul McCabe said, adding the dead at the school were all in one room.
   
One victim was identified by a friend as teacher Neva Rogers, 62, the Minneapolis Star-Tribune newspaper reported.
   
The gunman fired at doors of classrooms barricaded by terrified students and teachers, witnesses said.
   
"He came into the school and the first person he shot was the security officer at the door," said Molly Miron, editor of the Bemidji Pioneer newspaper. "One of the students told me he pointed his gun at a boy and then changed his mind, smiled, waved at him, and shot somebody else."
   
The authorities did not release the gunman's name. The FBI described him as a juvenile, but did not specify his age.
   
Police, alerted to the massacre when students used cell phones to call for help, said they exchanged gunfire with the gunman who ducked into a classroom and shot himself.
   
Witnesses said he was armed with a shotgun or rifle and at least one handgun.
   
The gunman's motive was not immediately known, the FBI said, though a classmate told a local television station that he had spoken a year ago of wanting to "shoot up the school."
   
It was the deadliest US school shooting since the April 20, 1999, Columbine High School massacre in Colorado in which 14 students - including the two killers - and a teacher died.
   
In 2002 a gunman in Erfurt, Germany, killed 13 teachers, two students and a policeman at the Gutenberg secondary school before killing himself.
   
Ojibwa tribe

The Minnesota reservation 100 km South of the Canadian border is controlled by the Ojibwa tribe, commonly known as the Chippewa, which says it has roughly 10,000 members, about half of whom live on the reservation.
   
The tribe runs its own affairs and operates casinos in the state and a small casino in Red Lake, 55 km North of Bemidji on the shores of Lower Red Lake. But the casinos are not as successful as others in more populous areas, unemployment on the reservation is high, and many residents are poor with few jobs other than some small industries, raising wild rice and fishing.
   
Before being settled by the Chippewa in the late 18th Century, Red Lake was the site of a major village of the Dakota tribe. It later became a fur trading outpost run by the British North West Co.
   
After the shooting, the school was evacuated and the reservation closed to outsiders.
   
Minnesota Governor Tim Pawlenty offered condolences to the families of the victims of "this senseless tragedy."
   
The shooting follows the March 12 shooting deaths of seven congregants at a church service near Milwaukee, Wisconsin, which ended when the gunman killed himself.
   
In 2003, a student at Rocori High School in central Minnesota gunned down two classmates. He is awaiting trial.