At least four people were wounded overnight in a shooting on the campus of the University of Southern California, police said early Thursday.
An officer with the Los Angeles Police Department confirmed there had been a shooting on campus and said four people had been taken to hospital, but could not immediately provide further details.
USC said on its website that a suspect was in custody following the shooting, which occurred at 11:30 pm (0630 GMT) Wednesday.
The campus emergency website urged students to stay away from the area, citing an "ongoing police investigation."
The LA Times reported that "several" people were shot at a Halloween party on the campus.
The private university in Los Angeles has more than 38,000 students and boasts the largest number of international students of any US university.