A former US college football player was arrested Monday and charged with murder after three members of the current University of Virginia team were shot dead at the school a few hours south of the US capital.
The latest outburst of campus gun violence came as four people were found dead in a separate incident near the University of Idaho.
Police chief Timothy Longo told a news conference that a 22-year-old UVA student, Christopher Darnell Jones Jr, had been taken into custody on suspicion of carrying out the shooting Sunday night and faces murder charges.
Police in Henrico County said Jones was arrested "without incident" Monday morning in a suburb of Richmond, about 75 miles (120 kilometers) southeast of the UVA campus in Charlottesville.
The shooting took place on a bus while students were returning from a field trip, according to UVA president Jim Ryan, who said all three of those who died were members of the school's football team.
Two other students were wounded, Ryan said, and one of them was in critical condition.
"This is a sad, shocking and tragic day for our UVA community," Ryan said. "My heart is broken for the victims and their families."
The campus in Charlottesville, about 100 miles (160 kilometers) southwest of Washington, was locked down for hours while police searched for Jones, a former UVA football player listed on the Cavaliers' 2018 roster as a first-year running back.
Longo said Jones had previously been brought to the attention of the school's "threat assessment" team after a report that he possessed a gun but no weapon was discovered.
The three players who died were identified as Cavaliers wide receivers Lavel Davis Jr and Devin Chandler, and linebacker D'Sean Perry.
The White House sent its condolences to families of the victims of the "senseless shooting" and called on Congress to pass stricter gun control laws.
"Too many families across America are bearing the awful burden of gun violence," the White House said. "We need to enact an assault weapons ban to get weapons of war off America's streets."
- Idaho college homicide -
US Senator Tim Kaine of Virginia said he was "heartbroken to hear of another Virginia community devastated by gun violence."
In 2007, Virginia Tech became the scene of the worst school shooting on record in the United States when a 23-year-old student killed 32 students and faculty members before committing suicide.
More than 2,000 miles to the west in the Rocky Mountain state of Idaho, police were investigating a separate incident in which four students were found dead Sunday in a home near the University of Idaho campus, believed to be the "victims of homicide."
Officers responded to a call in the town of Moscow, near the university, about an unconscious person.
"Upon arrival, officers discovered four individuals who were deceased," police said in a statement.
Authorities did not release other details including the cause of death, and no arrests have been made in the case.
"It is with deep sadness that I share with you that the university was notified today of the death of four University of Idaho students living off-campus believed to be victims of homicide," University of Idaho president Scott Green said in a statement.
School shootings are alarmingly common as part of a broader wave of gun violence in the United States, where the proliferation of firearms has soared in recent years.
In May an 18-year-old gunman burst into Robb Elementary School in Uvalde, Texas, with a semi-automatic rifle and killed 19 students and two teachers, in an attack that shocked the nation and renewed calls for gun reform.