Providence (United States) (AFP) - US authorities on Sunday detained a person of interest in the mass shooting at Brown University that left two people dead and nine others wounded, the latest in a long line of school attacks nationwide.

A shooter opened fire on Saturday at the elite Ivy League university in Providence, Rhode Island in a building where exams were taking place, triggering a campus lockdown and launching an hours-long hunt for the suspect.

Providence Mayor Brett Smiley told an early Sunday press conference that a “person of interest” had been detained and the shelter-in-place order lifted.

Police Colonel Oscar Perez added that authorities were “not at this point” looking for anyone else in relation to the attack.

Of the nine wounded, one was in critical condition, seven were in stable condition and one was discharged, Smiley said.

Joseph Oduro, a teaching assistant at Brown, said he was in a campus auditorium when the gunman entered.

“I was standing in the front of the auditorium, and he came through the back, so we pretty much directly made eye contact, and then as soon as that happened, I looked at my students and signaled them to come to the front, and then I just ducked,” Oduro told CNN.

“He came in, pointed the gun and then screamed something… then he just started shooting right after that.”

Police released 10 seconds of footage of the suspect, seen from behind, walking briskly down a deserted street after opening fire inside a first-floor classroom.

“It is shocking and so terribly sad. I know the students here, many of whom were sheltering for many, many hours last night,” Smiley said later on CNN. “They’re all incredibly shaken up.”

Final exams scheduled for Sunday were postponed, university officials said.

- Latest mass shooting -

Brown University President Christina Paxson confirmed in a letter to community members that all 11 victims were students.

The attack is the latest incident of mass shooting in a country where attempts to restrict access to firearms face political deadlock.

“This should not be normal,” Smiley said on CNN. “This should not be the case that every community needs to prepare for something like this to happen. And I certainly never thought that it would actually happen in Providence, although we were well prepared for it.”

There have been more than 300 mass shootings in the United States so far this year, according to the Gun Violence Archive, which defines a mass shooting as four or more people shot.

During an event at the White House on Sunday afternoon, US President Donald Trump spoke briefly about the shooting at the Ivy League campus.

“Great school… really one of the greatest schools anywhere in the world. Things can happen,” the president said.

“So to the nine injured, get well fast, and to the families of those two that are no longer with us, I pay my deepest regards and respects from the United States of America.”

- Emergency alert -

Brown, which has a student body of about 11,000, sent an emergency alert at 4:22 pm (2122 GMT) on Saturday reporting “an active shooter near Barus and Holley Engineering,” which is home to the engineering and physics departments. Two exams had been scheduled at the time.

“Lock doors, silence phones and stay hidden until further notice,” the university said.

Law enforcement and first responders swarmed the scene, with local news station WPRI reporting “clothing and blood on the sidewalk.”

The deadliest school shooting in US history took place at Virginia Tech on April 16, 2007, when South Korean student Seung-Hui Cho killed 32 people and wounded 17 others before taking his own life.