SAN DIEGO -- Student achievement trumped diversity in a battle over educational goals as the San Diego Unified School District Board of Education Tuesday approved an expansion of a charter for a City Heights school that mainly serves Somalis.

Approval allows the K-8 Iftin Charter School at 5465 El Cajon Blvd. to expand to high school grades as well.

District staff had recommended denial of the expansion plan because Iftin's student body was 93 percent African-American -- nearly entirely Somali -- in a neighborhood that's 45 percent Hispanic and just 14 percent black. State law calls for charter schools to strive for a student body that reflects the district's demographics.

Bashir Hassan, a member of Iftin's governing board, said the racial imbalance is a product of being a relatively new and small school.

Students in recent immigrant families are "flourishing" because of the school, which has posted significant improvements in test scores in the past year, Hassan said.

"Overall, the school is doing a very good job," Hassan said.

The expansion of the charter passed on a 3-2 vote, with Katherine Nakamura and John de Beck dissenting.

The school has had four years to improve diversity in the primary grades but has not done so, said Nakamura.

"It's not just racial, it's cultural isolation" that doesn't fit America's values, Nakamura said.

Iftin currently has 211 pupils. There are nine Hispanics, three whites and three Asians.

Shelia Jackson, the board president, said school officials have been "pounding the pavement" in an effort to improve diversity.

The board also unanimously approved a policy to increase student access to world language programs beginning in kindergarten.

The policy will allow staffers to develop a program to bring the district into line with new University of California guidelines. It will also increase bilingual educational opportunities for students for whom English is not their primary language.