A person who was detained over the shooting that killed two students at Brown University was to be released, US officials said on Sunday.

"Shortly, we will be releasing the person of interest who had been detained earlier today," said Brett Smiley, mayor of Providence, Rhode Island -- where the university is located.

US authorities early on Sunday detained a person of interest in the mass shooting at Brown University that left two people dead and nine others wounded, the latest in a long line of school attacks nationwide.