A gunman killed two people and wounded nine others on Saturday at Brown University, plunging the eastern US campus into lockdown as hundreds of police hunted the suspect late into the night.
The streets around the university in the state of Rhode Island were filled with emergency vehicles hours after the gunfire at a building where exams were taking place.
The shooting is the latest in a long line of school attacks in the United States, where attempts to restrict access to firearms face political deadlock.
Witness Katie Sun told the Brown Daily Herald student newspaper she was studying in a nearby building when she heard gunfire. She ran to her dorm, leaving all her belongings behind.
"It was honestly quite terrifying. The shots seemed like they were coming from... where the classrooms are," she said.
Six hours after the shooting, the gunman was still at large, and some 400 police ranging from FBI agents to campus cops swarmed the quaint New England campus.
"I can confirm that there are two individuals who have died this afternoon, and there are another eight in critical status, though stable," Providence, Rhode Island Mayor Brett Smiley told a news conference.
A ninth person who "received fragments from the shooting" was later taken to the hospital, authorities said.
Police released ten seconds of footage of the suspect walking briskly down a deserted street, seen from behind after opening fire inside a first-floor classroom.
University officials stressed that the campus was still in lockdown as midnight approached.
Ten of the 11 victims were students, Brown University President Christina Paxson said in a late night briefing.
"My heart breaks for the students who were looking forward to a holiday break and instead are dealing with another horrifying mass shooting," Rhode Island Senator Sheldon Whitehouse posted on X.
Exams
The shooting took place at the Barus and Holley building, home to the engineering and physics departments, on the campus of the Ivy League university.
Two exams had been scheduled to take place in the building at the time of the shooting, the university said.
Law enforcement described the suspect as a man dressed all in black.
"We're utilizing every resource possible to find this suspect. The shelter in place is still in order and I urge people to take that very seriously. Please do not come to the area," Deputy Police Chief Timothy O'Hara said.
The gunman was last seen leaving the building, and no weapon had been recovered, authorities said.
Brown sent an emergency alert at 4:22 pm (2122 GMT) reporting "an active shooter near Barus and Holley Engineering."
"Lock doors, silence phones and stay hidden until further notice," it said.
Law enforcement and first responders swarmed the scene, with local news station WPRI reporting clothing and blood on the sidewalk.
The FBI was providing "all capabilities necessary," Director Kash Patel said on X.
Agents from the Bureau of Alcohol, Tobacco, Firearms and Explosives were also responding.
US President Donald Trump had been briefed on the shooting.
"What a terrible thing it is," he said. "All we can do right now is pray for the victims."
Brown University in Providence, near Boston, has about 11,000 students.
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.
