The Supreme Court told the high court of Oklahoma on Thursday to clarify a new state law restricting the use of the RU-486 abortion pill, possibly setting the stage for a ruling on how far states can go in regulating the practice of abortion.

Legislators in several states, including Oklahoma, have passed laws to strictly regulate the practice of abortion. Among them are measures that require all women seeking abortions to undergo an ultrasound test.

But the Oklahoma Supreme Court blocked these laws from taking effect last year, saying they conflicted with a 1992 U.S. Supreme Court decision on abortion.

On Thursday, the justices, in their last meeting until late September, granted in part an appeal from Oklahoma's lawyers, but then sent the case back for the state court to further explain how the RU-486 law would work.

TRIBUNE Washington Bureau