Protesters at a North Carolina university are calling for changes to a part of campus dedicated to anything-goes speech after someone painted racist graffiti directed at President Barack Obama.

North Carolina State students blocked access overnight to the Free Expression Tunnel, a major pedestrian thoroughfare that connects two parts of the Raleigh campus divided by railroad tracks.

University spokesman Keith Nichols says the students had stopped their blockade by late Thursday morning, although some protesters remained.

Chancellor Randy Woodson talked with the protesters at the tunnel earlier in the morning, and plans to meet with students later in the day.

He has condemned the graffiti, which has been painted over.