
The shooting occurred around 11:45pm Wednesday outside the Ronald Tutor Campus Center, where about 100 people had gathered for a party hosted by a student organization.
USC police Capt. David Carlisle said two men outside the holiday party were arguing shortly before midnight when one pulled a gun and opened fire.
One man was shot several times and critically wounded. Three bystanders were left with non-life threatening injuries. None of those involved were USC students.
Police said the suspects were arrested about 10 minutes after the shooting.
The Los Angeles Times reports USC sent a text alert telling students to stay inside. Hours later, another text said the threat was over and classes would go on as scheduled.
The private university in Los Angeles has more than 38,000 students and boasts the largest number of international students of any US university.