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 in black and may have been wearing a mask. The shooting happened at the Barus and Holley building, part of Brown University's engineering school, during a review session led by a teaching assistant. In the immediate aftermath of the shooting, it was reported that a suspect had been taken into custody but it was quickly confirmed that the man held had no involvement in the attack. The university has canceled exams scheduled for the day. Governor Dan McKee and President Donald Trump both expressed their condolences, calling the shooting a tragedy while the community grieves and rallies together.