An appeals court Wednesday upheld Mississippi's method of lethal injection, rejecting arguments from death row inmates who opposed the state's plan to use drugs not specifically approved by state law.

The 5th Circuit U.S. Court of Appeals ruled that U.S. District Judge Henry T. Wingate ruled incorrectly in August when he issued a preliminary injunction blocking the state from executing prisoners.

The opinion by Circuit Judge Jennifer Walker Elrod rejected arguments by death row prisoners that Mississippi can't execute them because the state no longer will be using the particular class of drugs required by state law. She wrote that if inmates want to pursue such claims, they should do so in state court.

Mississippi law requires a three-drug process, with an "ultra-short-acting barbiturate" followed by a paralyzing agent and a drug that stops an inmate's heart. But Mississippi and other states had increasing difficulty obtaining such drugs after 2010, as manufacturers began refusing to sell it for executions.