At least two people have been killed and nine more were injured in a shooting at an engineering building in Brown University, USA, a law enforcement official said.
The Ivy League school issued an active shooter alert and urged students and staff to take shelter during the second day of final exams.
Police did not immediately release details about the victims' conditions or the circumstances of the shooting.
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President Donald Trump confirmed he had been briefed on the shooting.
"What a terrible thing it is," he told reporters.
"All we can do right now is pray for the victims and for those that were very badly hurt.
"We'll inform you later as to what's happening, but it's a shame."
He later shared a post on his Truth Social account, saying the FBI were on the scene.
"God bless the victims and the families of the victims!" the post concluded.
Providence Mayor Brett Smiley confirmed two people had been killed and another eight people had been injured.
It is understood the injured have been taken to hospital, where they remain in a critical but stable condition.
He later reported a ninth person was injured, but that their injuries were non-life-threatening.
Police confirmed in a press conference they are looking for a male suspect who left the scene on foot.
The suspect was a male wearing dark clothing, last seen leaving the engineering building where the attack happened, Deputy Chief of Police Timothy O'Hara said.
The FBI is assisting the Providence Police Department in the hunt for the accused gunman.
Smiley said there is a lot of "fear and anxiety" within the community without a suspect in custody.
A person preliminarily thought to be involved was detained earlier but was later determined to have no involvement.
Smiley urged residents to remain indoors and to listen to advice from authorities.
Authorities believe the shooter used a handgun, according to a law enforcement official who was not authorised to discuss an ongoing investigation and spoke on condition of anonymity.
"The unthinkable has happened," Democratic Rhode Island Governor Dan McKee said.
University officials initially told students and staff that a suspect was in custody, before later saying that was not the case and that police were still searching for a suspect or suspects, according to alerts issued through Brown's emergency notification system.
The reported shooting occurred near the Barus & Holley building, a seven-story complex that houses the university's School of Engineering and physics department.
According to the university's website, the building includes more than 100 laboratories, dozens of classrooms and offices.
Engineering design exams were under way in the building when the shooting occurred.
"We know there is a lot of fear and concern and uncertainty in the community right now," the university said in a statement.
"Law enforcement is actively working to identify the deceased victims, and the hospital personnel are also working to identify those transported to the hospital.
As a reminder, please continue to take all steps to remain safe. Follow the instructions of law enforcement personnel and avoid the area. The safety of our community is foremost."
A police officer warned members of the media to take cover in vehicles because the area was still an active scene.
"We're still getting information about what's going on, but we're just telling people to lock their doors and to stay vigilant," said Providence Councilmember John Goncalves, whose ward includes the Brown campus.
"As a Brown alum, someone who loves the Brown community and represents this area, I'm heartbroken. My heart goes out to all the family members and the folks who've been impacted."
Officers carrying assault weapons and emergency vehicles lined many of the streets surrounding the engineering school.
Officials were still gathering information, said Kristy DosReis, chief public information officer for the city.
President Donald Trump said late in the afternoon that he has been briefed on the shooting.
"God bless the victims and the families of the victims!" he said on his social media site.
Trump told reporters that "all we can do right now is pray for the victims."
"It's a shame," he said in brief remarks at the White House.
Brown senior biochemistry student Alex Bruce was working on a final research project in his dorm directly across the street from the building when he heard sirens outside and received a text about an active shooter shortly after 4pm.
"I'm just in here shaking," he said, watching through the window as a half-dozen armed officers in tactical gear surrounded his dorm.
He said he feared for a friend who he thought was inside the engineering building at the time.
Students in a nearby lab hid under desks and turned off the lights after receiving an alert about the shooting, said Chiangheng Chien, a doctoral student in engineering who was about a block away from the scene.
Mari Camara, 20, a junior from New York City, was coming out of the library and rushed inside a taqueria to seek shelter.
She spent more than three hours there, texting friends while police searched the campus.
The Ivy League school is a private, non-profit institution with about 7300 undergraduates and just over 3000 graduate students, according to its website.
Saturday was the second day of final exams for the fall semester.
Reported wth Associated Press and CNN
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