(CNN) -- Arkansas' Supreme Court on Friday afternoon stopped any more same-sex marriages in the state, a court spokeswoman said, leaving the legal status of more than 400 gay and lesbian couples who got marriage licenses in limbo.
This development stems from 21 couples' legal challenge of Amendment 83 to the Arkansas Constitution, arguing that it violates their federal and state rights of equal protection and privacy.
Pulaski County Circuit Judge Chris Piazza ruled in their favor last Friday. But same-sex marriage was back up in the air after the state Supreme Court said Wednesday it couldn't decide whether to grant an emergency stay because Piazza's decision was "not final."
The county judge updated his order Thursday, adding that his decision allowing same-sex marriage took effect immediately. Pulaski County, at least, was issuing marriage licenses to same-sex couples by Thursday afternoon.
Supreme Court spokeswoman Stephanie Harris told CNN that more than 400 same-sex couples got marriage licenses in the state since last week's original ruling. She said Friday that the legal status of any of these marriages is unclear.
CNN first learned of the state Supreme Court's issuance of an emergency stay -- which is in effect while its judges consider the appeal of Piazza's ruling in full -- via Twitter.
The Arkansas case is an entirely in-state matter, involving a local county court and the state's Supreme Court. But it's similar to a spate of federal rulings in recent months that have struck down other states' bans on same-sex marriage.
In those cases, U.S. district judges ruled that the marriage restrictions violate the federal Constitution's equal protection guarantee. But none of these decisions are in effect now, because either those judges stayed their rulings pending appeals or appellate courts did the same.
There were a few states, including Michigan and Utah, in which same-sex couples married before higher courts stepped in to issue emergency stays. That's what happened in Arkansas.
Carl Tobias, a constitutional law professor at the University of Richmond, said Friday that he expects more challenges in state courts to same-sex marriage prohibitions. Still, Tobias thinks advocates are more likely to take their fight to federal court.
"Plaintiffs have preferred to sue in federal courts in the apparent belief that they are a more favorable venue, or that federal judges will view their rights more broadly," said Tobias.