Murder and suicide at campus of University of California, Los Angeles, likely to intensify a national debate over gun control, following similar incidents across the US in which dozens have been killed.
Another shooting incident took place at an American institute of education on Wednesday, when two men were killed at the University of California, Los Angeles, in what is being termed as a murder-suicide.
Gunshots rang out through a section of the campus a little before 10am US time, causing panic among students and teachers who barricaded themselves in classrooms or wherever they could find a place to hide.
Police officers with rifles arrived and started a door-to-door search, while university officials ordered the campus locked down.
Los Angeles Police Department Chief Charlie Beck, told reporters a gun was recovered at the scene.
"A homicide and a suicide occurred. The situation appears to be entirely contained. There are no suspects outstanding and no continuing threat to UCLA's campus."
Officials did not give further details.
UCLA, with more than 43,000 enrolled students, is located in the Westwood section of Los Angeles and is one of the more well-regarded schools in California, known for its successful sports program.
Bioengineering student Bahjat Alirani said police were yelling at people to run from the scene.
"I was in Boelter Hall to take a final and I exit the staircase to see SWAT-looking police yelling at everyone to evacuate immediately," Alirani told Reuters.
After media reported the incident it began trending on social media.
Terrified students shared pictures from inside the university.
At least three city blocks leading into the campus were filled with dozens of emergency vehicles.
Camouflaged officers with rifles, bulletproof vests and helmets surrounded the area of the shooting.
Someone hiding in the university's IT room shared snaps from a CCTV camera showing police officers in action.
People following the incident on Facebook immediately began debating gun control – with gun rights activists preempting calls for tighter control that might ensue.
Between 2013 and 2015, there were 160 shootings in US schools in which 59 people, mostly students, were killed, according to Every Town Research.
US President Barrack Obama has led efforts to introduce stricter gun regulation.
But he has been frustrated by lawmakers in Congress.
A Reuters/Ipsos poll earlier this year found that half of all Americans support Obama's executive actions on gun control, with a majority saying they would back the next president in taking additional steps to tighten federal gun laws.
Presidential candidate Hillary Clinton has also pushed for measures to check gun violence.
Below are some of the worst school shootings in recent years, ranked by the number of dead:
April 16, 2007 – A gunman slaughters 32 people and kills himself at Virginia Tech, a university in Blacksburg, Virginia.
Dec. 14, 2012 – A gunman shoots his mother to death, then kills 20 children, six adults and himself at Sandy Hook Elementary School in Newtown, Connecticut.
April 20, 1999 – Two heavily armed teenagers go on a rampage at Columbine High School in Littleton, Colorado, shooting 12 students and a teacher to death and wounding more than 20 others before taking their own lives.
Oct. 1, 2015 – A gunman storms onto the campus of Umpqua Community College in southwest Oregon and opens fire, killing nine people before police shoot him to death.
April 2, 2012 – A former student kills seven students at Oikos University, a small Christian school in Oakland, California. The suspect is awaiting trial.
Oct. 2, 2006 – A gunman kills five girls in a one-room Amish schoolhouse in Nickel Mines, Pennsylvania, before killing himself.