Unprecedented plans by Arkansas to execute eight death row inmates in 11-days have been blocked by a federal judge.
The state has said it will appeal against District Judge Kristine Baker's order to grant stays of execution.
The judge ruled that the executions should be delayed as there was a significant possibility the inmates involved could successfully challenge the state's plans.
Arkansas has been trying to hurry them through by the end of April as its supplies of one of the three lethal injection drugs it needs are set to expire.
In her ruling Judge Baker cited a constitutional amendment banning "cruel and unusual punishments".
She ruled that the accelerated time-scale involved did not give the inmates sufficient time to prepare their appeals.
But a spokesperson for Arkansas Attorney General Leslie Rutledge said the state will appeal against the ruling.
The spokesperson said: "It is unfortunate that a US district judge has chosen to side with the convicted prisoners in one of their many last-minute attempts to delay justice."
Earlier, in a separate court case , a temporary restraining order was issued after one of the drug companies involved objected to its product being used.
McKesson Medical Surgical said it had sold vercuronium bromide to Arkansas for medical purposes and that it was not supposed to be used for capital punishment.
The drug is used along with potassium chloride and midazolam. The midazolam is to sedate the inmate before the other two drugs paralyse the lungs and stop the heart.
Both sides have been involved in a flurry of legal action ahead of the planned executions.
A stay of execution had already been granted to Bruce Ward, an inmate who was due to be executed on Monday.
The 60-year-old was convicted of murdering a female convenience store worker and was sentenced to death 17 years ago.
His lawyers have said he is schizophrenic and does not understand what is happening to him.
If they go ahead, the planned executions would be the first in Arkansas for 12 years.
States across the US have struggled to carry out executions as they are finding it harder to get hold of supplies of the drugs they need.
Opponents of the death penalty point to a botched execution in Oklahoma in 2014 which left a prisoner writhing in pain for 40 minutes before he suffered a heart attack as an example why lethal injections should be banned.
Some states are now considering alternate means of execution, including the re-introduction of firing squads.