Police are investigating a shooting at the University of Arizona in Tucson, Arizona, where a gunman killed two people and wounded six others.
The shooting happened at about 10:00 am local time on Monday.
Two officers were killed and two others wounded, according to local police.
“There is no indication that the suspect, who we believe to be in his 20s, had a weapon,” Tucson police chief David A. Lucero said at a news conference.
Lucerra said the suspect was killed by a “high-powered rifle”.
The suspect is still at large and authorities are working to determine whether the shooting was “random”, Luceras office said in a statement.
“This incident does not appear to be a random act of violence, but a targeted act,” Lucerras office said.
The university’s campus was placed on lockdown and police evacuated about 200 students, faculty and staff from campus.
“Our thoughts and prayers are with the families of the victims,” a statement from the university said.
“We have an ongoing investigation into this shooting, and will share more information as it becomes available.”
A Facebook page for the campus, titled “A vigil for the victims of the shooting,” was set up to pay tribute to the victims.
The page has more than 100 people commenting on the event.
One person commented: “They will be missed dearly.
We can’t even begin to express our deepest condolences for their loss.”
The school is about 15 minutes north of Tucson, and has about 8,000 students.
The area is known as a safe haven for college students and the US Justice Department has designated it as a “safe haven” under the Deferred Action for Childhood Arrivals programme, or DACA, program.
The programme allows people brought to the US illegally as children to apply for a work permit, but only if they pass a background check.
The program has been criticized by Republicans and Democrats as an overreach by the Obama administration to help millions of undocumented immigrants who are eligible for a reprieve from deportation.
The Trump administration has defended the programme, saying it will make sure that “the border is secure” and will help “the economy”.
A spokesman for the White House said the US had “always had and will always have a policy of being a nation that respects all people, including the very many who are in the country illegally”.
The US Justice department has said it will consider an emergency application to temporarily grant deferred action for people brought illegally to the country as children, known as DREAMers, who would be allowed to stay in the US without fear of deportation.
US President Donald Trump has repeatedly said that he will grant DREAMer relief from deportation if he wins the November election.