A judge in Arkansas moved Friday to block the state from carrying out up to seven executions this month, deepening the turmoil that surrounds a planned pace of killing with no equal in the modern history of American capital punishment.

Judge Wendell Griffen of the Pulaski County Circuit Court issued a restraining order Friday that forbids the Arkansas authorities from using their supply of vecuronium bromide, one of three execution drugs the state planned to use. Hours earlier, the nation’s largest pharmaceutical company went to court to argue that the state had purchased the drug using a false pretense.

The judge scheduled a hearing for Tuesday morning, about 14 hours after the state had intended to carry out its first execution since 2005. The Arkansas attorney general’s office said the state would appeal the judge’s ruling, which threatened to derail a plan that once called for eight executions over the course of 10 days.

The restraining order surfaced during an afternoon and evening of legal chaos: The State Supreme Court issued a stay of execution for one death row prisoner, and a federal judge was also weighing a request to block the executions. Yet Judge Griffen’s order appeared to have the widest immediate effect, and it was the first to focus on the misgivings of the pharmaceutical industry.

