Virginia Tech police on Monday reported another instance of racist graffiti on campus, less than a week after students protested against what they see as institutional racism at the school.

On Saturday, police responded to West Ambler Johnston Hall, where someone had written "nigger" on a wall of the dormitory in black marker, Lt. Wendell Flinchum said.

Flinchum said he did not know how large the word was written and said he assumed it had been cleaned off the wall.

He said police have no suspects in the vandalism.

There have been several incidents of racist graffiti on campus at the school in the past few years and multiple incidents this semester.

Tech spokesman Mark Owczarski said the school would continue to look into this latest instance and said such incidents are not acceptable at Tech.

Owczarski added that Tech President Charles Steger has denounced racist graffiti at the school in the past. The university also adopted its Principles of Community in March 2005 reaffirming its commitment to diversity on campus.

But Shawn Braxton, head of the Virginia Tech chapter of the NAACP, said Tech needs to take a more active role to educate the community about problems with racism at the school.

"It's been happening often," Braxton said. "Basically this is the environment at Tech currently. We've been addressing these issues for a while."

Tech has a lower percentage of black students than all but two public, four-year colleges in the state.

About 150 students marched on Burruss Hall last week to protest what they see as institutional racism at Tech in the wake of the university's dismissal of Chris Clement, a black political science professor.

The university responded to the protests by vowing to form a task force on institutional approaches to race.

Staff writer Joe Eaton contributed to this report.