At least two people were killed and eight more critically injured in a shooting on Saturday in the area of Brown University in Providence, Rhode Island, the city’s mayor said at a news conference, after the school issued an active-shooter alert and urged students and staff to take shelter during the second day of final exams.

The mayor of Providence, Brett Smiley, told reporters at about 6.30pm local time that the 10 victims were all who were known at the time, but the “shooter or shooters” were still at large and the number of victims could change.

Rodney Chatman, Brown university’s police chief, described the shooting investigation as “a very fluid situation.”

The deputy chief of the Providence police, Timothy O’Hara, said that a suspect was “a male dressed in black”.

The university said in a message to the students and staff just after 6.30pm local time: “There are eight additional victims in critical, but stable condition at the hospital. There remains a shelter in place order. The shooter or shooters still are not in custody at this time. Law enforcement is active in the area.”

“The situation is ongoing, and all members of the community should continue to shelter in place,” the school added on its website.

A few minutes earlier, the school said that an “earlier report of a secondary shooting incident near Governor Street is unfounded”.

Officials initially said a suspect was in custody, before saying that was not in fact the case and police were still searching for a suspect or suspects.

Students were urged to shelter in place as police responded to the scene, and people were told to avoid the area. Officials cautioned that information remained preliminary as investigators worked to determine what had occurred.

Police were actively investigating and still gathering information from the scene, said Kristy DosReis, the chief public information officer for the city of Providence.

In remarks to reporters at the White House, Donald Trump said he’d been “fully briefed” on the situation.

“What a terrible thing it is. And all we can do right now is to pray for the victims and for those that were very badly hurt it looks like,” he said. “We’ll inform you later as to what’s happening. It’s a shame. It’s a shame. Just pray.”

US attorney general Pam Bondi said on X that the FBI and ATF agents “are on the scene of the tragic shooting at Brown University in Rhode Island. Please pray for all involved.”

The incident was reported near the Barus and Holley building, a seven-story structure that houses the school of engineering and physics department, according to the school’s website. It includes 117 laboratories, 150 offices, 15 classrooms and 29 labs.

“Urgent: There’s an active shooter,” the university’s alert system first warned students and staff at 4.22pm local time. “Lock doors, silence phones and stay hidden until further notice. Remember: RUN, if you are in the affected location, evacuate safely if you can; HIDE, if evacuation is not possible, take cover; FIGHT, as a last resort, take action to protect yourself. Stay tuned for further safety information.”

The Ivy League school is a private, non-profit institution with about 7,300 undergraduates and just more than 3,000 graduate students, according to its website.

Saturday was the second day of final exams for the fall semester.