DULUTH - Students walked out of a central Minnesota school district Wednesday in protest of a decision to block a tribal drum group from performing at a graduation ceremony, a blow to the Native American students who make up nearly a third of the graduating class.

The Hinckley-Finlayson school board voted Monday, basing the decision partly on advice from legal counsel. The drum group, which hoped to perform the Ojibwe traveling song, took part in last year's ceremony. The district says it would no longer allow it, or performances from any other extracurricular groups.

A memo to the board said the school district's attorney cited the establishment clause of the First Amendment, which says government should remain neutral on religion.

"It's demoralizing," said senior Kaiya Wilson, who will graduate this month. "I feel like they're sending a message that they get to pick and choose which cultures and what people they want included in their school."

The nearby Mille Lacs Band of Ojibwe argues the music of tribal drum groups is cultural rather than religious, and cited state universities, such as the University of Minnesota Duluth, that include them in their ceremonies.

"The tradition of tribal drums at graduations pays tribute to the students and provides them with a sense of accomplishment and honor from their home communities," Mille Lacs Band chief executive Melanie Benjamin said in a statement. "We thought we had reached a point where we didn't have to fight battles like this. I guess we were wrong."

District Superintendent Brian Masterson declined to speak but sent a statement on behalf of the school district. It said the decision wasn't made lightly, and the drum group was offered access to the school's Fine Arts Center to perform following the May 24 ceremony. The district is about 80 miles north of the Twin Cities.

"The district's goal at graduation time is to make all district seniors, and the families and community members who have supported them during their educational career, feel celebrated at graduation," the statement says, noting that excluding performances by extracurricular groups ensures "the graduation ceremony remains focused on the graduating students."

Nearly a quarter of the district's 950 students this year are Native American, about 20 of whom are set to graduate. Graduation rates for Native American students have historically been low, reflecting a history in which the federal government forced attendance at boarding schools where culture and language was stripped from generations of Native Americans.

Minnesota's graduation rate for Native American students is 61%. In Hinckley, it is nearly 80%.

Niiyo Gonzalez is a member of the St. Croix Chippewa Indians of Wisconsin and has two children enrolled in the school district. She said the exclusion is dismissive of Native American culture and the hard-earned success of Native students.

"We think about how difficult it is to be in an American, highly Westernized educational system," she said. "And to make our way through it and accomplish [graduation] is such an achievement. ... So if you're going to have music representative of your culture in a public ceremony, you're making choices about which culture to represent. We just want ours to be part of it."

Wilson, who plans to attend the Twin Cities campus of the University of Minnesota next year to study psychology and American Indian studies, is a citizen of the Michigan-based Grand Traverse Band of Ottawa and Chippewa Indians. She's started an online petition to have the performance reinstated.

"This has hurt so many people," she said.

The school board memo also cited disruption to the ceremony by those moving closer to watch performances, requests by other groups to perform and respect for peoples' time. The statement lists the ways the district supports its Native American students, including a spring powwow and a recently adopted smudging policy that allows the culturally significant Native American practice.