A manhunt is under way after two students were killed and nine other people were injured in a mass shooting at Brown University in Providence, Rhode Island.
The gunman opened fire in a classroom at around 16:00 local time (21:00 GMT) on Saturday, in a building where exams were taking place.
The university, one of the oldest and most prestigious in the US, was placed into lockdown as police searched for the gunman, who remains at large.
Students in parts of the campus are continuing to be told to shelter in place until police can escort them out of the area.
Officials from Rhode Island Hospital said most of the injured are in a critical but stable condition.
The identities of those killed or injured have not yet been released by officials.
This is a day that we hoped never would come to our community. It is deeply devastating for all of us, said Brown University President Christina Paxson in a statement.
Police have released limited information about the male suspect, including an identity or motive. It is not known if he has links to the university.
CCTV footage showed the suspect walking out of the building after the attack but his face cannot be seen.
Providence Deputy Police Chief Tim O'Hara said the suspect was dressed all in black and may have been wearing a mask. It is not known what type of firearm he used and it has not been recovered.
We're utilizing every resource possible to find this suspect, he added, with extra armed police resources drafted in to search the area.
The shooting happened at the Barus and Holley building, part of Brown University's engineering school. The attack transpired during a review session for an economics class.
Officials cleared the building on Saturday afternoon but found neither the suspect nor a weapon.
University exams scheduled for Saturday have been cancelled, provost Frank Doyle said.
President Donald Trump described the shooting as a terrible thing and called for prayers for the victims.
Brown University, part of the Ivy League, has more than 11,000 students and is located approximately 50 miles from Boston, MA.
The shooting marks one of many mass shootings in the US this year, with the total number standing at 389 according to gun violence tracking sites.
