(CNN) -- A student on Monday killed two of his grandparents, then went on a shooting rampage at his Minnesota high school, killing five people and wounding as many as 15 others before killing himself, officials said.
FBI Special Agent Paul McCabe told reporters the dead include a female teacher, a male security officer and four Red Lake High School students.
"We believe that one of those students is the shooter," McCabe said.
The school was evacuated and locked down, he said.
"At this time, we believe he was acting alone," McCabe said. He would not comment on a possible motive, saying, "It's far too early in the investigation."
The slain students were shot in one room, he said, adding that 14 to 15 other students were wounded.
"Apparently, he walked down the hallway shooting and then he entered a classroom, he shot several students and a teacher, then himself," said Roman Stately, with the Red Lake Fire Department, who arrived at the high school moments after the shootings.
Authorities discovered about an hour later that the boy had shot and killed his grandmother and grandfather, a veteran of the police force, Stately told KARE-TV.
Stately said the boy used his grandfather's police-issued weapon in the school rampage.
The shootings occurred about 3 p.m. (4 p.m. ET), in Red Lake High School, a school of 300 student that is on a sovereign Indian reservation within Beltrami County, about 25 miles north of Bemidji, a town of about 25,000 residents, many of them Ojibway Indians, he said.
The school is about 240 miles north of the Twin Cities, near the Canadian border.
__________________
in my heart you will always be
friends forever, you & me
i love you paul...you are not forgotten
Sgt. Paul A. Crough Jr. KIA:IRAQ