A gunman has killed two students and left eight fighting for their lives after opening fire at an American university.
The attacker struck at Brown University in Rhode Island on Saturday afternoon, targeting students who were revising for their final exams.
Armed police flooded the streets of Providence through the night hunting for the killer, who was caught on camera fleeing the Ivy League campus dressed entirely in black.
Officers locked down the area around the university and told residents to stay indoors as the search continued.
The massacre unfolded just after 4pm in the Barus & Holley building, a seven-storey block home to the engineering school and physics department.
CCTV footage shows a stocky man in a black coat, trousers and hat walking away from the scene with what appears to be a limp. He swings his right arm as he walks along Hope and Waterman streets, at one point putting his hand in his pocket.
Witnesses told police the shooter wore a grey camouflage mask, though this isn't visible in the grainy footage and his face cannot be seen.
Police chief Colonel Oscar L Perez Jnr said detectives are investigating whether specific students were targeted in the attack.
One witness said the gunman burst into a ground-floor classroom where an exam review session was underway, shouted something, then opened fire.
University president Christina H. Paxson struggled to contain her emotion as she addressed the tragedy.
"There are truly no words that can express the deep sorrow we are feeling for the victims of the shooting," Ms Paxson said.
"We lost two community members today who were fatal victims of the shooting, and at this point, we know there are at least eight additional victims who were transported to the hospital... our hearts are with their families."
She described the manhunt as "a source of tremendous fear and anxiety across our community right now", adding: "This is a day that we hoped never would come to our community."
Providence was brought to a standstill as theatres, restaurants and hotels went into lockdown. Mayor Brett Smiley deployed at least 400 officers onto the streets with squad cars positioned outside key venues.
"We have no reason to believe that there are any additional threats at this time," Mr Smiley said.
Deputy police chief Tim O'Hara described the suspect as "male, all dressed in black" and "could be in his 30s". No weapon has been recovered and officers don't yet know what type of gun was used.
President Donald Trump said he had been briefed on the attack and promised federal support for the investigation.
"I've been fully briefed on the Brown University situation," he told reporters at the White House. "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."
Vice President JD Vance wrote on X that he was "thinking of and praying for the victims tonight", while House Speaker Mike Johnson said: "May God protect everyone affected and bring comfort to their families and loved ones."
Rhode Island governor Dan McKee said: "Our capital city experienced an unthinkable tragedy today. Our hearts are with the people of Providence and all those impacted."
He confirmed a shelter-in-place order remained in force across the university area, adding: "We're making every resource available as an active investigation continues."
Fourth-year students had gathered in the classroom to prepare for upcoming finals when the shooting erupted, according to local broadcaster WPRI.
Engineering PhD student Chiang-Heng Chien described the terrifying moments after gunfire rang out.
"We decided to turn the lights off and close all the doors and hide under our desks," he told television station WJAR.
Another student was in the Engineering Research Centre when she heard shots at around 4.10pm and fled, abandoning her belongings.
"It was honestly quite terrifying," she told student newspaper The Brown Daily Herald.
CNN obtained footage showing students huddled together inside campus buildings, some on their phones as armed response teams and ambulances raced to the scene.
Brown University police chief Rodney Chapman said officers arrived "minutes" after the first 999 call but had received "no warning" the attack was about to happen.
Fire chief Derek Silva initially said 10 people had been shot. Two died at the scene while eight were rushed to hospital in critical but stable condition.
A ninth victim later came forward with non-life-threatening injuries from bullet fragments. They are expected to recover fully.
At least one of the critically wounded students remained in a fight for life late Saturday night.
FBI director Kash Patel confirmed his agents were on the ground and pledged to "provide all capabilities necessary".
"Please pray for all those involved. We will update with more information as we are able," Mr Patel wrote on X.
