The state of Arkansas on Friday ran into a pair of new legal obstacles to its plan to carry out lethal injections on seven murderers in an unprecedented series of executions before the end of the month.

The Arkansas Supreme Court granted an emergency stay of execution for Bruce Ward, 60, who was convicted of killing a convenience store clerk, and less than two hours later the executions of six other murderers were put on hold when an Arkansas circuit judge issued a temporary restraining order.

The judge's restraining order barred the state from administering one of three drugs it planned to use in the executions, which are scheduled to begin on Monday and stretch over 11 days.

Attorney General Leslie Rutledge plans to file an emergency request for the Supreme Court to vacate that order, a spokesman said, allowing the injections to commence.

The state, which has not carried out a death sentence in 12 years, scheduled the fast-paced executions in order to beat the expiration date on its batch of one of the drugs used in its lethal injection cocktail.

An eighth inmate who had been scheduled to die also won a stay earlier, removing him from the list for April execution.

Lawyers for all of the convicts have asked a federal court in Little Rock to block the executions, arguing the state's rush to the death chamber was unconstitutional and reckless. The US judge has yet to issue a ruling on the broader case.

The state Supreme Court offered no comment in staying Ward's execution. His lawyers had argued he was schizophrenic and the court should take that into consideration before any final decision on his execution.

"He deserves a day in court for that, but in Arkansas the rules do not permit that," Scott Braden, a lawyer with the Arkansas Federal Defender Office, said after the stay was granted.

The attorney general was evaluating how to proceed in Ward's case, a spokesman said in a statement.