Yelling "Expose racial tension! It's time to change the system," a group of students marched across the University of Maryland campus yesterday to the police station with a list of demands.

Ever since a party last month ended with the arrests of three people, the College Park campus has been embroiled in a debate about race, equality and integration. Yesterday, on the 50th anniversary of Rosa Parks's refusal to give up her seat on a bus, student protesters called for an end to racial injustice.

The protest came after an early morning incident Nov. 13, when the U-Md. Department of Public Safety responded to a noise complaint about a party of about 100 people, most of them black, at the New Leonardtown apartments.

The campus police arrested two 19-year-old men who are U-Md. students and a 23-year-old man who is not. The charges included assault, resisting arrest and disorderly conduct, and two officers were treated for minor injuries, said Maj. Cathy Atwell, a campus police spokeswoman.

Some students told a different story, of police waving nightsticks, squirting pepper spray on students and showing their guns. "They were pulling out their pistols, and the two young men [the arrested students] were peaceful," said sophomore Chris Graham-Egbo, a black student who said the incident was another sign of a major problem on campus.

Yesterday, a few dozen students demanded an apology from police, an investigation and a pledge to end police brutality and racial profiling, and they insisted that all charges be dropped.

"We are talking about when will it stop," said freshman Safiya Ransome, a black student, who began to cry during the protest as she remembered a family friend who she said was killed by police years ago. "We've been facing this problem for years, years, years."

Atwell said Police Chief Kenneth W. Krouse had seen the list of demands and had contacted one of the students to set up a time to talk about the issues.

The students said their larger purpose was to bring attention to racial tensions just below the surface at U-Md., a topic that many on campus continue to discuss, whatever their feelings about the police and the party that triggered the controversy.

"Personally, I tend to give the benefit of the doubt to the police," said Greg Oberson, 26, a white graduate student. "It was probably a pretty chaotic situation." But he agreed that the campus tends to split into racial groups. He said sees it in his engineering program, where he doesn't usually hang out with the Asian students but with other whites.

"People do tend to stay with their own type or race" at U-Md., said Andrew Kurland, a white junior. "They sit with the people they identify with."

Several said the issues aren't unusual. "Actually, it's more integrated than where I came from," said Jason Kiviat, a freshman who grew up on Long Island.

After the party, stories in the campus paper -- and some heated online exchanges and e-mails -- got people talking. An earlier protest brought out about 150 people to the center of campus.

Brandon Dula, assistant director for multicultural involvement at U-Md., said university officials are planning a discussion Wednesday about diversity and cross-cultural interaction on campus. He said that there has been progress and that when he went to college in the 1970s, life was far more segregated.

Yesterday, Maj. Paul Dillon of the campus police stood on the steps of the station watching the students waving signs and making speeches. "We support people's right to voice their opinion on campus," he said.

Krouse wrote a letter to the Diamondback, the campus newspaper, asking people not to judge the department by a single incident. He reminded readers of efforts that police have made to "embrace the diversity that encompasses our campus community," including helping to design a response to hate and bias incidents and increasing minority participation in hiring.

Atwell said an internal investigation of the Nov. 13 arrests is underway, as is routine after any incident in which force is used.

Protest organizer Daniel Lewkowicz, a white sophomore, said he is troubled by what seemed like excessive force by police and by segregation at U-Md. He said he hopes the campus community will make changes before the semester ends.

"When things get calm again," Lewkowicz said, "people get complacent."

Students demonstrate at the campus police station. Protesters said they want authorities to drop charges against men arrested at a campus party.Safiya Ransome, 18, left, is comforted by a friend. Ransome said the situation reminded her of a family friend who was killed by police years ago.