More than half of Maryland’s black students attend schools where the vast majority of students are nonwhite and poor, according to a report released Thursday that documents intensifying segregation patterns in the state’s public schools over two decades.

Fifty-four percent of Maryland’s black students were enrolled in schools where at least 90 percent of students were members of racial and ethnic minorities in 2010, up from about a third in 1989.

In Prince George’s County — where white enrollment decreased from 28 percent to 4 percent during those two decades — nine of 10 black students attend a school where at least 90 percent of students are minorities. Nearly four of 10 black students go to what the Civil Rights Project report calls “apartheid schools,” where 99 percent of students are minorities.

“We are seeing a lot of racial change . . . and not much effort to do anything about it,” said Gary Orfield, co-director of the Civil Rights Project, which is based at UCLA.

Schools with high concentrations of minority students tend to be disproportionately poor and have fewer experienced teachers, inferior facilities, less-challenging classes, and lower graduation rates, according to the report.

The Civil Rights Project’s analysis of federal data is the second in a series of 12 reports examining school segregation in the eastern United States more than a half-century after the Supreme Court’s decision in Brown v. Board of Education made school segregation illegal. The first report focused on Virginia, and it found far fewer schools with high concentrations of minority or poor students.

A national report by the same organization found that Maryland was the sixth-most-segregated state in the country for black students.

Maryland schools are becoming less diverse even as the state grows more multiracial. The share of white students in Maryland schools decreased from 62 percent to 43 percent from 1989 to 2010. While African American students remained about a third of enrollment, the proportion of Latino students grew from 2 percent to 12 percent.

By 2010, 37 percent of Latino students were attending what the report calls “intensely segregated schools,” where more than 90 percent of students are minorities.

In Montgomery County, where white enrollment decreased from nearly two-thirds of school rolls in 1989 to 35 percent by 2010, about one in four Latino or African American students is enrolled in an intensely segregated school.

Nearly all of the more than 400 schools in Maryland that were 99 percent or 100 percent minority were in Prince George’s or Baltimore City, according to a separate analysis by The Washington Post of federal enrollment data. A handful of schools were in Montgomery and Baltimore counties.

In the decades since Brown v. Board of Education, school systems have tried various ways to desegregate schools, the report said. In Montgomery, magnet schools and programs have become the predominant strategy to encourage voluntary desegregation, though their effect has been limited, the report said. An “inclusionary zoning” housing policy in the county also has contributed to diversity in schools by requiring developers to set aside units for sale at below-market prices.

Prince George’s tried mandatory busing and later magnet schools. But it dismantled three dozen magnet programs in 2004, in part because diversity became an elusive goal after thousands of white families left or opted to send their children to private schools.

In the mid-1970s, Prince George’s experienced what was “the largest black suburban migration in the country,” Orfield said, making it for a time a diverse county. “Now it’s thoroughly re-segregated.”

Ted Mellnik contributed to this report.