“We have confirmation of two people killed for now,” police spokeswoman Jenny Houser told AFP.
Officials said the two victims, both males, were found inside Boelter Hall, which is part of the school of engineering, located in the center of the campus.
“It is possible one of the victims is the shooter,” James Herren, head of the UCLA police department, told reporters, saying the possibility of a murder-suicide had not been ruled out.
“What we know is that a shooting happened,” Captain Andy Neiman, of the Los Angeles police department, earlier told reporters. “The message to everybody on campus is to shelter in place.
“Lock yourself in a safe place until authorities can get to you or provide you a message that it’s safe to come out.”
Police said the shooting was reported shortly before 10 am, prompting a campus-wide lockdown.
Dozens of police cars and tactical response teams as well as federal agents rushed to the site as helicopters hovered overhead.
Authorities also placed the city of Los Angeles on a tactical alert which means that police throughout the area can be mobilized.
Officials urged people to avoid the area around the campus. A nearby elementary school was also placed on lockdown.
Some 43,000 students are enrolled at the massive UCLA campus, according to its website.