Providence police were searching late Saturday for a gunman who killed two people and wounded at least eight others on Brown University’s Rhode Island campus during finals week.

Members of the university community and nearby residents were urged to shelter in place while authorities looked for the shooter. “All we have as a suspect is a male dressed in black,” said the deputy chief of the Providence police, Timothy O’Hara, at a televised press conference.

The mayor of Providence, Brett Smiley, told reporters, “I can confirm that there are two individuals who have died this afternoon, and there are another eight in critical status, though stable, at Rhode Island Hospital.”

News reports quoted unnamed police sources saying the shooting took place in the Engineering building shortly after 4 p.m. while students were writing their final exams and that the suspect had left the building.

In an earlier statement, the university said it had “informed our community to shelter in place, by locking doors, silencing phones and staying hidden until further notice,” adding that “it does remains an active crime scene and law enforcement continues to search for the suspect.”

President Trump, returning to the White House from the Army-Navy football game at nearby Annapolis, Maryland, told reporters as he had been briefed on the situation.

“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,” he said. “It’s a shame. Just pray. Thank you very much.”

Mr. Trump had earlier posted that the suspect was in custody but corrected that in a second post after authorities in Providence reversed an erroneous report.