Police are not looking for anyone else over the shooting that wounded nine people at the Ivy League school in the northeastern US.

Police in Providence, Rhode Island, have detained a “person of interest” after a manhunt for a gunman who killed two people at Brown University, officials say.

At a news conference on Sunday, Police Colonel Oscar Perez said the individual had been detained that morning and officers were not currently looking for anyone else in relation to the shooting at the Ivy League university in the northeastern United States.

Officials have not released the identity of the person of interest.

Nine people were wounded on Saturday, seven of them critically, when a suspect with a firearm entered a building where students were taking exams and opened fire.

The shooting sparked a manhunt involving more than 400 law enforcement personnel, including agents from the Federal Bureau of Investigation and the Bureau of Alcohol, Tobacco, Firearms and Explosives, while the campus was placed under lockdown as the search took place.

Students hid under desks for hours after warnings of an active shooter were released.

Brown said in an advisory on Sunday that police had lifted a shelter-in-place order for the campus although police remained at the location and still considered it an active crime scene.

Access to parts of the campus remained restricted on Sunday as police maintained a security perimeter around Minden Hall and nearby apartment buildings, the university said.

Officials had earlier released a video of the suspect, a male, possibly in his 30s, who was dressed in black.

Providence Deputy Police Chief Timothy O’Hara said on Saturday that the gunman may have worn a mask and investigators had retrieved shell casings from the scene.

Detectives were looking into why the location was targeted, Perez told reporters. The incident was the second deadly gun attack at a US university in recent days after a shooting at Kentucky State University on Tuesday.

The Gun Violence Archive, which defines mass shootings as any incident in which four or more people are shot, has documented 389 such incidents in the US so far this year, including at least six at schools.

Last year, more than 500 mass shootings were recorded in the US.