The person who died after being shot at a high school in the US state of Tennessee was a student who started a shoot-out with police, according to federal law enforcement.

Officers raced to Austin-East Magnet High School in Knoxville on Monday afternoon after receiving reports of multiple gunshot victims and a person possibly carrying a weapon.

They found the gunman in a restroom and went in when he refused to come out, according to a statement from the Tennessee Bureau of Investigation.

"As officers entered the restroom, the subject reportedly fired shots, striking an officer. One officer returned fire," said the statement, released late Monday.

"The subject was pronounced dead at the scene and has since been identified as a student. The officer who was shot was transported to a local hospital for treatment."

Knoxville Mayor Indya Kincannon visited the wounded officer in hospital shortly after the shooting and told reporters outside that he was conscious and in good spirits.

"He's going to be okay. And I thanked him for putting his life on the line to protect the students and staff at the school," said the mayor.

"And he said he'd rather that he be hurt than anybody else, and is in very good spirits and looking forward to the successful surgery."

The United States has been plagued by school shootings since the massacre at Columbine, in the state of Colorado, in April 1999.

Monday's shooting in Tennessee comes on the heels of President Joe Biden unveiling proposals to expand gun control.

Biden branded gun violence an "epidemic" and an "international embarrassment" during his April 8 speech.