Three teenagers were killed and eight other people wounded in a shooting on Tuesday at Oxford High School in suburban Oakland County, about 45 miles north of Detroit in the American state of Michigan.

The three killed were a 16-year-old boy and two girls aged 14 and 17. The eight wounded, including a teacher, were taken to a hospital.

Some of wounded are in critical condition, including a 14-year-old on a ventilator, Oakland County Sheriff Michael Bouchard said late Tuesday.

The suspect, a 15-year-old sophomore at the high school, is in custody. He was arrested within minutes of deputies arriving at the school in response to a flood of 911 calls about the attack, which happened shortly before 1 p.m. His parents have hired an attorney and have not permitted him to talk to the police.

Police have identified the gun as a 9mm Sig Sauer, which Bouchard said was bought by the suspect's father on November 26. 

Bouchard said the suspect had practiced shooting with the gun and posted pictures of it and the target, but why the boy's father bought the gun remained unclear.

The suspect "fired multiple shots," Undersheriff Michael McCabe told reporters at the scene. "Somewhere in the area of 15 to 20."

"The whole thing lasted five minutes," McCabe said.

McCabe said he was aware of allegations circulating on social media that there had been threats of a shooting at the roughly 1,700-student school before Tuesday's attack, but he cautioned against believing that narrative until investigators can look into it.

Oakland County Prosecutor Karen McDonald promised swift justice, saying in a statement: "It is our intent to review it (the investigation) thoroughly and issue appropriate charges quickly. The suspect will remain in custody pending those charges."

Gun control is one of the most divisive issues in the U.S., and the fresh school shooting will likely revive efforts to prevent gun violence that has long plagued the country.

"This is a uniquely American problem that we need to address," said Michigan Governor Gretchen Whitmer, who rushed to the scene and appeared with McCabe before the media.

President Joe Biden expressed condolences to the bereaved families while touring a Minnesota technical college. "My heart goes out to the families enduring the unimaginable grief of losing a loved one," he said.

(With input from Reuters, AP)