UPDATE: 11.15AM

A student has been shot dead by police after allegedly opening fire on officers responding to a report of a gunman at a Tennessee high school.

Tennessee Bureau of Investigation Director David B Rausch said police found the student 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.

Police returned fire and the student died at the school. 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,” Mr Rausch said.

In the latest episode of gun violence in the United States since mid-March, there were initial fears of multiple gunshot victims as the incident unfolded at the Knoxville school on Monday at 3.15pm local time.

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.

Knoxville police said the injured officer, who was reportedly shot in the hip, was expected to survive.

“He is conscious and in good spirts,” Knoxville Mayor Indya Kincannon told CBS News.

“He’s going to be OK. I thanked him for putting his life on the line to protect sutdents and staff at the school. He said he’d rather be hurt than anybody else.”

Investigators did not immediately identify the suspect or slain victim except to say they were both male. It was not immediately clear if either attended Austin-East Magnet School.

“Upon approach of the subject, shots were fired. A KPD officer was struck at least one time and transported to the (University of Tennessee) Medical Centre with injuries that are not expected to be life-threatening.

“One male was pronounced deceased at the scene, while another was detained for further investigation.”

The police department initially reported “multiple gunshot victims” in the attack.

“Knox County Schools is responding to a shooting that occurred this afternoon at Austin-East Magnet High School,” Knoxville schools superintendent Bob Thomas said on Twitter.

“We are gathering information about this tragic situation and will provide additional information as soon as possible.

“The school building has been secured and students who were not involved in the incident have been released to their families.”

The public school, located on Martin Luther King Jr Avenue, has 685 students. Photo: AAP

US Bureau of Alcohol Tobacco and Firearms agents were en route to assist other law enforcement agencies, the bureau’s Nashville office said on Twitter.

Police established a reunification site for families of the students at the baseball field behind the high school.

One mother who had been separated from her daughter was waiting elsewhere near the school and was relieved to receive a text message from her that she was safe.

In other shootings since mid-March, a man opened fire at the cabinet-making plant in Texas where he worked last week, killing one person and wounding six others before he was arrested.

Eight people were slain at Atlanta-area spas, 10 people at a supermarket in Boulder, Colorado, and four people, including a 9-year-old boy at a real estate office in Orange, California.

Mr 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,” Mr 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.”

-with agencies