Updated

Two Oklahoma death row inmates scheduled to be executed next month have sued state corrections officials to obtain details about the lethal drugs that will be used to execute them, including their source.

The lawsuit filed Wednesday by Charles Warner and Clayton Lockett challenges the constitutionality of a state law prohibiting disclosure of the identity of people who provide drugs to be used in executions. It also asks that their executions be blocked until the information is provided.

Lockett is to be executed March 20 for the 1999 shooting death of a 19-year-old Perry woman. Warner is to be executed on March 27 for the 1997 death of his girlfriend's 11-month-old daughter.

Oklahoma Department of Corrections spokesman Jerry Massie didn't immediately return a call seeking comment.