OKLAHOMA CITY (AP) — Attorneys on Friday asked a federal appeals court to delay the executions of four Oklahoma inmates while the court considers their joint appeal.

The attorneys filed emergency motions seeking the delays with the 10th U.S. Circuit Court of Appeals in Colorado.

Among the inmates is Charles Warner, who is scheduled to be executed next Thursday for the 1997 killing of an 11-month-old child. It would be the state's first execution since the botched April lethal injection of inmate Clayton Lockett, who took nearly an hour to die after an intravenous line failed. Three more executions are scheduled through March.

The inmates contend the use of the sedative midazolam as the first in a three-drug combination presents a serious risk of subjecting them to unconstitutional pain and suffering. A federal judge in Oklahoma City last month rejected those claims, but the inmates appealed and want the 10th Circuit to take a closer look at their arguments.

"This is really a complicated case. There's a lot of evidence, and these guys deserve the benefit of a full hearing," said Dale Baich, an attorney with the federal public defender's office who represents the inmates.

Attorneys for the state say the Oklahoma Department of Corrections has ramped up training, written new execution procedures and renovated the death chamber at the Oklahoma State Penitentiary to prevent a repeat of Lockett's problematic execution.

The head of Oklahoma's prison system, Robert Patton, said Thursday that the state is prepared to execute Warner next week.