Two people were killed Wednesday morning in a murder-suicide at the University of California, Los Angeles, shootings that led police to lock down the campus for about two hours as officers searched and cleared the area.

“The campus is now safe,” Charlie Beck, chief of the Los Angeles Police Department, said at a news conference Wednesday afternoon. “The issue that occurred has been contained.”

Reports of several shots fired at the city campus started coming in at about 10 a.m. local time, and authorities quickly locked down the campus of 43,000 students. Police urged people to stay away as they considered it a possible active-shooter situation, and students barricaded themselves in classrooms and dorms as dozens of local and federal law enforcement officials streamed in.

Some UCLA students were still in class this week as the semester is wrapping up, with the main commencement scheduled for June 10.

Police said they could not confirm the identities of the two people killed, their relationship or their roles at the school, saying only that they were both men. The Los Angeles Times reported later Wednesday that an engineering professor was killed in the shooting. Beck said both men were found in a small office in the engineering building.

“Many, many questions are unanswered at this point,” Beck said, noting that it was possible there was a suicide note at the scene.

What we know about the UCLA shooter (Gillian Brockell/The Washington Post)

After a prolonged search involving law enforcement officers on the campus and surrounding areas, police ultimately determined that there were no remaining suspects. The university said the campus reopened a short time after 12 p.m., but classes were canceled for the remainder of the day.

Beck said police would continue to search the building where the shooting occurred even after students were released from lockdown.

An attorney in Orange County, who asked to remain anonymous because of the sensitivity of the situation, was worried when he heard reports of a shooter in the engineering building where his father, a professor in mechanical and aerospace engineering at UCLA, has an office. In a text exchange, his father described having to hold a door closed while shots were fired.

“My dad is now out safe, thankfully,” he said in a telephone interview. “They locked down in their offices ‘til SWAT teams broke down the doors and escorted everyone out of the building.”

The law enforcement response on Wednesday was typical of what is seen after shootings and reports of gunshots at schools. Initial information is often fluid and uncertain, as police work to figure out if they are responding to another mass shooting — like the rampage at Roseburg, Ore., last fall — or a murder-suicide, as occurred at a Phoenix high school this year.

Schools often respond quickly to potential violence, running shelter-in-place drills during the year and locking down facilities when there are reports of gunfire. They also have increasingly become targets for threats of bombs and violence, as callers across the country this year have disrupted classes and stoked fear in dozens of schools.

“This horrific event, at an institution dedicated to learning and mutual understanding, reminds us once again of the fragility of a peaceful society,” Mayor Eric Garcetti (D) said in a statement. “Thankfully, the campus is now safe — but I am heartbroken by the sight of SWAT teams running down campus avenues normally filled with students, and angered by the fear that one person with a firearm can inflict on a community.”

Due to the lockdown at UCLA Wednesday, police across Los Angeles were placed on tactical alert, according to the LAPD. The LAPD and FBI both responded to the scene, along with agents from the Bureau of Alcohol, Tobacco and Firearms. The President was briefed aboard Air Force One on the shooting, according to the White House.

On social media, people reported hiding in classrooms waiting for updates.

Jennifer Jenkins, Matt Zapotosky and David Nakamura contributed to this report.

This is a developing story and will be updated.