Little Rock, Ark. — A new Arkansas law requiring public classrooms to display the Ten Commandments cannot be enforced in a handful of the state's largest school districts where parents brought challenges on the grounds that it violates the separation of church and state, a federal judge ruled Monday.

But the ruling by U.S. District Judge Timothy L. Brooks, an appointee of former President Barack Obama, only narrowly applied to four of the state's 237 districts. That left the impact of the decision limited as thousands of Arkansas students prepared to return to class this month.

The injunction is the latest legal turn in a widening push in Republican-led states to give religion a bigger presence in public schools.

Texas and Louisiana have passed similar laws requiring classrooms to display the Ten Commandments and the issue is expected to eventually reach the U.S. Supreme Court.

"Why would Arkansas pass an obviously unconstitutional law?" Brooks wrote in his 35-page ruling. "Most likely because the state is part of a coordinated strategy among several states to inject Christian religious doctrine into public-school classrooms."

The Arkansas law, signed earlier this year by Republican Gov. Sarah Huckabee Sanders, takes effect Tuesday and requires the Ten Commandments to be prominently displayed in public school classrooms and libraries.

The suit was filed on behalf of the families by the American Civil Liberties Union, Americans United for the Separation of Church and State and the Freedom from Religion Foundation.

"The court saw through this attempt to impose religious doctrine in public schools and upheld every student's right to learn free from government-imposed faith," John L. Williams, legal director of ACLU of Arkansas said in a statement. "We're proud to stand with our clients - families of many different backgrounds - who simply want their kids to get an education."

Attorney General Tim Griffin, whose office defended the law, said he was reviewing the decision and assessing legal options.

The lawsuit says the requirement violates the families' constitutional rights and pressures students into observing a religion favored by the state.

It wasn't immediately clear if the groups would seek an broader block of the law beyond the four districts. ACLU of Arkansas Executive Director Holly Bailey said through a spokesperson that "it is clear from this order and long established law that all should refrain from posting" the Ten Commandments in public school classrooms.

The similar requirements enacted in Texas and Louisiana are also being challenged in court.

A group of families and faith leaders filed a lawsuit seeking to block Texas' requirements days after it was signed into law.

Last month in Louisiana - the first state that mandated the Ten Commandments be displayed in classrooms - a panel of three appellate judges ruled that the law was unconstitutional.

The ruling marked a major win for civil liberties groups who say the law violates the separation of church and state. But the legal battle is likely far from over.

Many, including Louisiana Attorney General Liz Murrill, expect the case to eventually reach the U.S. Supreme Court. Most recently, Murrill filed a petition seeking the full U.S. Court of Appeals for the 5th Circuit's review in the matter.