Two campus police officers were shot and killed at a college in the US state of Virginia Tuesday, while one student was killed and another wounded in a shooting at a school in Minnesota the same day. 

Two agents, a campus law enforcement officer and a campus safety officer, were shot before the suspect fled the scene at the college in Virginia, Virginia State Police said in a statement on Twitter. 

Multiple law enforcement agencies arrived on the campus of Bridgewater College around 1:20 pm (1820 GMT) in response to active shooter reports, according to the same statement, which the school also posted to its website. 

The suspect, a 27-year-old man named Alexander Wyatt Campbell, was later apprehended, Virginia State Police said, adding that he had a "non-life-threatening gunshot wound."

It was not yet clear if he had been shot by police or if the wound was self-inflicted. He has already been charged with murder, police said.

The town of Bridgewater, about two and a half hours south of the US capital of Washington and where Bridgewater College is located, sent out an alert around 1:30 pm warning of an active shooter situation, local media reported. 

The school issued an all-clear notice on its website around 4:30 pm. 

One student, 21-year-old, Kasey Truslow, told the Washington Post she heard a gunshot outside the window of a classroom building. 

"After the second shot, we got on the floor. We remained on the floor for an hour," she said. 

Virginia Governor Glen Youngkin tweeted, "I have been briefed on the situation at Bridgewater College. The shooter is in custody and state and local police are on the scene."

- 'Sickening' -

The officers were identified by the school as John Painter and J.J. Jefferson. 

The pair "were shot and killed on campus while protecting us," a statement from college president David Bushman on its website said. 

"These officers were close friends, known to many of us as the 'dynamic duo.' John was J.J.’s best man in his wedding this year. They were beloved by students, faculty and staff. I hurt for their families and loved ones, as I know we all do," the statement continued.

Bridgewater Mayor Ted Flory posted a statement on the small town's website.

"Bridgewater is shocked by today’s senseless violence at Bridgewater College," Flory said. "We are heartbroken by the needless injuries and loss of life."

President Joe Biden, who has called on Congress to enact tougher gun control laws, tweeted about the shooting, saying he and his wife "are praying for the families of those lost."

"Gun violence against law enforcement officers is sickening, and it must end," he said.

The shooting in Minnesota occurred in the town of Richfield just outside of Minneapolis around noon, officials said, leaving one student dead and another wounded.

The attackers opened fire on the students on a sidewalk outside the South Education Center before speeding away in a car, Richfield Police Chief Jay Henthorne told the StarTribune newspaper.

Two suspects were later arrested, the paper said, noting that friends of the victim had identified the slain student as Jamari Rice, who some local journalists said was the son of Black Lives Matter activist Cortez Rice.

Cortez Rice was arrested last year and charged with attempting to intimidate a judge handling the trial of ex-police officer Kim Potter officer who killed a Black man in April when she said she mixed up her taser with her pistol during a traffic stop.

US university goes online after mass shooting threat

A major US university moved its classes online Tuesday after a former philosophy lecturer posted a video apparently threatening a mass shooting on campus.

UCLA in Los Angeles told its 44,500-strong student body that classes would be held remotely after Matthew Harris put an 800-page screed and video on the internet.

Harris was arrested in Boulder, Colorado, police chief Maris Herold told reporters.

"Upon reviewing parts of the manifesto, we identified thousands of references to violence, stating things such as killing, death, murder, shootings, bombs, schoolyard massacre in Boulder," she said.

"The level of violence that we saw in the manifesto was obviously so alarming. We have not made connections yet across states, and that's why we have federal partners looking at this as well. But I can tell you it's very violent, very disturbing."

According to the Daily Bruin, a newspaper published by UCLA students, university police began investigating Harris after he sent messages to several individuals in the philosophy department.

These included a link to a video entitled "Philosophy UCLA (Mass Shooting)" as well as an 800-page diatribe containing threats. 

Harris had been placed on administrative leave last year after being accused of sending a video with pornographic content to a student, the Daily Bruin reported.

Mass shootings, particularly in schools, shopping malls and places of worship, are a recurring problem in the United States that successive governments have failed to curb.

Despite a majority of the US public being in favor of stricter gun control rules, attempts to limit access to firearms are regularly stymied by a powerful gun lobby, which cites a constitutional right to bear arms.

Gun violence claimed more than 44,000 lives in 2021, including suicides, according to the Gun Violence Archive.