(CNN) -- Striking back against resegregation in schools, education leaders gathered Friday in Raleigh, North Carolina, to hear the president of the nation's oldest civil rights organization speak about the national state of education.
NAACP President Benjamin Todd Jealous sounded a warning to representatives of more than 2,200 branches and units during the keynote address the Daisy Bates Education Summit, which began Thursday and ends Saturday.
"School boards across this country are rolling the clock back to the time before Brown vs. the Board of Education," Jealous said in a statement. "The NAACP will not let this happen."
School resegregation is at its highest rate in four decades, according to the National Association for the Advancement of Colored People.
The NAACP has cited a case in North Carolina.
The U.S. Department of Education's civil rights office will begin an investigation next week into Wake County Public Schools, according to Beth Glenn, the group's national education director.
Glenn told CNN that the North Carolina NAACP, as part of a coalition with 93 other community organizations, filed a complaint with the Education Department in an effort to block the new school board majority from moving forward with assigning students under a neighborhood zone system that would replace a diversity-based plan.
In July, police in Raleigh arrested 19 people at a rancorous school board meeting where protesters accused the Wake County School Board of adopting the plan.
The board voted in March to stop the decade-long practice of socio-economic school assignment and assign students to their neighborhood schools.
Currently 85 percent of the system's 143,000 students attend a school within five miles of their home, said system spokesman Michael Evans. Another 12 to 13 percent attend magnet schools and the remaining 3 percent are assigned based on their income level and growth issues.
Wake County is a booming school system with unprecedented growth that often requires the students to attend different schools, Evans said.
David Forbes, a minister who spoke at a rally before the March meeting said, "'Neighborhood schools' is a trick word to re-segregate a city that worked hard to bring about a progressive new possibility."
The NAACP meeting also dealt with other issues.
Workshops held during the three-day conference are based on four reform principles of the group's national agenda, including access to high quality pre-K, expanded learning opportunities beyond regular school days, targeted funding so spending goes to students who need it most, and training and support for teachers, said Glenn.
"We want to get people energized," Glenn said. "This is an ongoing process," she added.
The summit was named in honor of Daisy Bates, former president of the Arkansas State Conference of the NAACP and advisor to the Little Rock Nine, the statement said. Those nine students desegregated Little Rock Central High School in 1957.