A 17-year-old girl is dead after a violent assault at a school just south of Edmonton.
RCMP say it happened at about 10 a.m. at Christ the King School in Leduc, which has about 350 students in grades 9 to 12.
Mounties say the girl was airlifted to hospital, where she died of her injuries, and her death is being investigated as a homicide.
Bob Young, mayor of Leduc, said the girl was stabbed and all schools in the area were locked down until police made an arrest.
Police said a 19-year-old man, who was a student at the same school, was taken into custody about two hours later at another location.
He says all schools in the area were locked down until officers made the arrest.
RCMP say they are not looking for any more suspects.
Insp. Dale Kendall said the two students were known to each other, but she wouldn't say if it's believed that the attack was targeted. She also won't confirm if the girl was stabbed.
"This is a true tragedy. It is incomprehensible that an act such as this could happen here in our close-knit community of Leduc," she told a news conference Monday.
"If there ever is a time to support your neighbours and hug your loved ones, this is it."
The school's police resource officer was not present at the time of the attack, Kendall added.
Major crimes investigators were taking control of the case and officers were not looking for more suspects.
Education Minister Adriana LaGrange said in a statement that she was heartbroken to hear of a tragedy on school grounds. She said mental health supports would be available.
The Saint Thomas Aquinas Roman Catholic School Division said there would be no classes at the school on Tuesday and a trauma support team would there for the rest of the week.
“We cannot express deeply enough the sorrow we feel for the family members, friends and staff members who have lost a loved one today," the division's superintendent, Charlie Bouchard, said in a release.