By Dennis RomeroA gunman killed two people and injured nine others after opening fire at Brown University’s engineering and physics building in Providence, Rhode Island, on Saturday, officials said.The unidentified gunman left after the shooting at the Barus & Holley building, on the eastern edge of the campus, Commander Timothy O’Hara, deputy chief of Providence police, said Saturday night. People in the area were advised to shelter in place amid an active manhunt. A spokesperson Brown University Health, which operates Rhode Island Hospital, where the injured were being treated, said seven people remained in critical condition and one had been stabilized. An 11th victim was identified hours after the shooting, and had non-life-threatening injuries from fragments, officials said.Manhunt for shooter described as ‘a male dressed in black’O’Hara described the gunman only as “a male dressed in black.”The attack was reported just after 4 p.m. at Brown’s Barus & Holley building, a seven-story structure home to much of the university’ engineering and physics study and research, officials said.It happened inside a first-floor classroom at the Barus & Holley building, officials said. The outer doors of the building were open at the time because exams were taking place, Providence Mayor Brett Smiley said. “It is unknown how he entered the building, but we do know that he exited the Hope Street side of that complex,” O’Hara said.Students are escorted by law enforcement officers to a building at Brown University on Saturday.Charles Krupa / APShelter in place in effectAn alert on Brown’s Emergency Information website instructed people to lock doors, silence phones and stay safe. A shelter-in-place advisory was still in effect Saturday night for the campus — including any of the 11,000 enrolled students who remained at the Ivy League university — and the Providence neighborhoods surrounding the school, Smiley said.On Saturday afternoon, officials walked back an earlier alert stating someone was taken into custody, leaving people in the city of roughly 190,000 in fear and uncertainty. Students hid under desksBrown is in the middle of final exams, which began Friday, continued Saturday and were scheduled to be held through next weekend, according to the university’s academic calendar.University President Christina H. Paxson said in a message to the school’s community that the shooting marked “a deeply tragic day for Brown, our families and our local community.”Chiang-Heng Chien, a Ph.D engineering student who was working at a campus lab, said people hid under their desks as shots rang out.”We decided to turn the lights off and close all the doors and hide under our desks,” Chiang-Heng Chien told NBC affiliate WJAR of Providence.Police at 6:20 p.m. clearing the Barus and Holley building at Brown University.Mark Patinkin / Providence Journal / USA Today NetworkAfter two hours, police moved in and told those in the lab to get out as fast as possible as they cleared the building in their search for the attacker, Chien said.Smiley said Saturday night that he lives “about a block away” from where the violence unfolded.He said he saw lights and sirens zooming past his house and O’Hara called him to give him an update.“Sadly, today is a day that the city of Providence and the state of Rhode Island prayed would never come,” Smiley said. “We’ve heard about horrific acts of gun violence and active shooter situations in other places, but not here.”President asks for prayers as federal agencies aid in responseSpeaking after he disembarked from Marine One at the White House Saturday night, President Donald Trump expressed sorrow.“What a terrible thing it is, and all we can do right now is pray for the victims and for those that were very badly hurt,” Trump said.State and local agencies were responding to the shooting, as were federal resources, including FBI personnel and agents from the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives. Both FBI Director Kash Patel and Attorney General Pam Bondi also asked for prayers. Rhode Island Gov. Dan McKee called the attack “an unthinkable tragedy.””Our hearts are with the people of Providence and all those impacted,” he said on X.This is a developing story. Please check back for updates.Dennis RomeroDennis Romero is a breaking news reporter for NBC News Digital. Insiya Gandhi and Phil Helsel contributed.