Supreme Court allows Texas abortion law. It's the most restrictive in the nation.

The court voted 5-4 early Thursday to deny an emergency appeal from abortion providers and others that sought to block enforcement of the law that went into effect Wednesday.

The Texas law, signed by Republican Gov. Greg Abbott in May, prohibits abortions once medical professionals can detect cardiac activity, usually around six weeks and before most women know they're pregnant.

"In reaching this conclusion, we stress that we do not purport to resolve definitively any jurisdictional or substantive claim in the applicants' lawsuit. In particular, this order is not based on any conclusion about the constitutionality of Texas's law, and in no way limits other procedurally proper challenges to the Texas law, including in Texas state courts," the court said in the unsigned order.

Chief Justice John Roberts, Justice Stephen Breyer, Justice Sonia Sotomayor and Justice Elena Kagan dissented.

Texas lawmakers wrote the law to evade federal court review by allowing private citizens to bring civil lawsuits in state court against anyone involved in an abortion, other than the patient. Other abortion laws are enforced by state and local officials, with criminal sanctions possible.

After a federal appeals court refused to allow a prompt review of the law before it took effect, the measure's opponents sought Supreme Court review.