Tennessee Bureau of Investigation Director David B. Rausch says police found the pupil in a bathroom at Austin-East Magnet High School in Knoxville, about 290 kilometres east of Nashville.

They ordered him out but he wouldn't comply and that's when he reportedly opened fire, Rausch said on Monday.

Police fired back.

The student died at the school and an officer was wounded and taken into surgery, authorities said. No one else was hurt.

"It's a sad day for Knoxville and it's tough for Austin-East," Rausch said.

The shooting comes as the community reels from off-campus gun violence that has left three Austin-East students dead this year and as more classrooms are re-opening to students after months of remote learning.

The nation has seen series of mass shootings in recent weeks, including eight people killed at three Atlanta-area massage businesses on March 16 and 10 people killed at Colorado supermarket on March 22.

Knox County Schools restarted in-person learning in January but Austin-East Magnet High School went back to virtual instruction briefly in February after the spate of shooting deaths of students.

The school will be closed again on Tuesday and Wednesday.

Speaking outside a hospital, Knoxville Mayor Indya Kincannon told WATE-TV she spoke with the wounded officer and he was conscious and in good spirits.

Kincannon, a former Knox County Schools board president, spoke at a February press conference about the gun violence that took the lives of three Austin-East students less than three weeks apart this year.

Two of the victims were 15, the other 16.

"I know that school is a safe place," Kincannon said at that time, according to the Knoxville News Sentinel.

"It's a place where people are learning. ... The issues with violence are happening in the community and it's affecting kids when they're outside of the school."

Australian Associated Press