Students at North Carolina State University in Raleigh are blocking access to a tunnel because of racist graffiti painted inside.
WRAL-TV reports that students painted the tunnel black overnight Wednesday to remove racist and anti-gay graffiti involving President Barack Obama.
A group of students also linked arms in the tunnel and prevented anyone from passing through.
The Free Expression Tunnel is used by students to comment on any issue. It's also a major thoroughfare on campus.
The protesters say they'll continue their blockade until the university adopts stricter controls on what can be written in the tunnel.
Chancellor Randy Woodson condemned the graffiti Tuesday. A sign at the tunnel asks students to refrain from offensive messages.