At least three people were wounded in a shooting incident this afternoon in a computer lab at South Mountain Community College, in Phoenix, and an unidentified gunman has been captured, according to the East Valley Tribune, a local newspaper that is regularly updating its coverage on its Web site.

The shooting followed a loud argument in a room that may have had as many as 50 people in it, eyewitnesses told the newspaper, but it was unclear if the gunman and his victims knew each other, or even if they were students or faculty members. Their names were not immediately disclosed by the police, but two were listed in critical condition.

The 8,000-student college’s Web site said that classes had been canceled and the campus put on “lockdown status” for the rest of today.

This is the third major shooting this year on an American campus. On February 8, a student at Louisiana Technical College at Baton Rouge killed two classmates and then herself. Less than a week later, a gunman at Northern Illinois University killed five people and wounded 16 before taking his own life. So far, at least, the shooting in Phoenix has not resulted in fatalities. —Andrew Mytelka