JACKSON (AP) — Fewer Mississippi schools have reached the top accreditation levels this year than last year, new rankings show.

Mississippi Superintendent of Education Hank Bounds said the results of standardized tests have flatlined, and the state Department of Education is putting in place a more rigorous curriculum and assessment system this year.

The department released this year’s preliminary school-by-school results of the state and federal accountability systems Thursday. The Board of Education must approve the results before they become final.

The school achievement levels — Level 1 is low-performing, Level 5 is superior — are based on standardized tests that students took in the spring. Test results were released about three weeks ago, with achievement and improvement taken into account. They also are used to grade progress under federal No Child Left Behind guidelines.

Thirty-one fewer schools are rated Level 4 or 5 this year than last year. The number of schools rated Level 3, 2 or 1 has increased.

Thirty-four more schools than last year joined the ranks of under- and low-performing schools.

The state had 228 Level 5 schools in 2006. That has decreased to 207 this year.

In 2006, there were 225 Level 4 schools. This year’s results show 215 Level 4 schools, or 26 percent.

Beth Sewell, executive to the superintendent for instructional programs and services, said the state’s 11 Level 1 priority schools — up from three last year — will receive extra attention from the state to try to help them score higher next year.

She said Department of Education employees ‘‘go into the school district and just do a comprehensive evaluation of the central office and the school itself.’’

Federal No Child Left Behind standards require schools to meet ‘‘adequate yearly progress’’ goals of increasing percentages of students performing at grade level in reading, language and math, and one other category — graduation rate for high schools and attendance for elementary and middle schools. They must meet those goals not only for all students, but also five racial categories, special education, limited English speakers and economically disadvantaged students.

Schools that don’t meet those goals for two years in a row go on a ‘‘school improvement’’ list. Schools must meet goals for two years in a row to get off the list.

Each year, the sanctions against the schools increase, beginning with requiring them to offer parents the option of choosing other public schools within the district. Closing a school is the most severe option.

Also Thursday, the Mississippi Commission on School Accreditation released the names of seven school districts that need to make improvements.

The Hazlehurst City, Holly Springs, Prentiss County and Tunica County school districts were moved from accredited to advised status, while the Jefferson Davis and North Panola school districts were downgraded from advised status to probation. The Holmes County School District will remain on probation.

A downgrade comes only after the Department of Education finds a number of serious deficiencies in the district’s management or leadership, academic achievement and/or financial practices.

Each district has issues to be addressed, including problems with facilities, between school boards and superintendents, staff promotion and retention, incorrect accounting practices and professional development plans.

Those districts that don’t already have corrective action plans have 60 days to come up with one to address their deficiencies. The advised status and probation periods can be indefinite. However, a district’s status can be upgraded almost immediately after improvements are made.

Districts that don’t try to improve risk completely losing their accreditation with the state – meaning credits earned by students would not be recognized by other schools, including colleges and universities.

With corrective action, though, districts can regain their accredited status, officials said. ———