A person of interest has been detained in connection with a US shooting at Brown University that left two people dead, police said.

Nine others were injured when a gunman opened fire at the university in Providence on Saturday.

Police confirmed on Sunday a person had been detained, and an earlier order for people on the Brown campus and surrounding areas to shelter had been lifted.

Of those injured, medics reported that one person was in critical condition, six were 'critical but stable', and two others sustained less severe injuries.

The gunman began shooting in a classroom at around 16:00 local time (21:00 GMT) on Saturday in the Holley engineering building at the eastern end of Brown's campus, according to officials.

The identities of the deceased and the injured have not yet been disclosed. Brown University President Christina Paxson stated in a press briefing that all victims were students.

Police had earlier released CCTV footage showing a male suspect wearing all black clothing walking away from the scene. A search of the building revealed no firearm was found.