AUSTIN, Tex. — A panel of federal judges in San Antonio has ruled that a handful of Texas congressional districts drawn by the Republican-dominated state Legislature in 2011 discriminated against black and Hispanic voters and violated the Voting Rights Act and the Constitution.

The ruling striking down the maps was made late Friday. It is the latest development in a long-running and racially charged redistricting case that locked Democratic lawmakers, minority groups, the Obama administration and the Texas Republican leadership in a legal battle for nearly six years. Democrats and civil-rights lawyers accused the majority-white Texas Republican leadership of drawing district maps in ways that diluted the voting power of Democratic-leaning minority voters, accusations that Republicans denied.

“The court’s decision exposes the Texas Legislature’s illegal effort to dilute the vote of Texas Latinos,” said Nina Perales, the vice president of litigation for the Mexican American Legal Defense and Educational Fund, which represented a coalition of Latino organizations that sued Texas over the redistricting maps. “Moving forward, the ruling will help protect Latinos from manipulation of district lines in order to reduce their political clout.”

The next steps in the case were unclear. Texas is likely to appeal the decision, and because of the legal dynamics, any appeal would go directly to the Supreme Court. The process of redrawing the maps may be delayed not only by an appeal but also because the San Antonio panel has yet to rule on another aspect of the case, the district maps drawn for the state’s House of Representatives.