The US Supreme Court late Tuesday halted the execution of a Mississippi prisoner just moments before he was set to die, officials from the state Department of Corrections said. Executions have been effectively placed on hold across the United States until the Supreme Court rules on whether lethal injections -- used in virtually all US executions -- are "cruel and unusual" punishment, as banned under the US constitution.

Earl Wesley Berry was set to be executed at 6 pm (2300 GMT Tuesday), but the procedure was halted when the Mississippi Department of Corrections received the ruling from the Supreme Court ordering a stay of execution at 5:41 pm (2241 GMT).

"Now that the United States Supreme Court has deemed the method of execution needs to be reviewed, the state (of Mississippi) will await the final order of the court," read a Department of Corrections statement.

"The agency will work within any newly established guidelines to ensure that executions are carried out in a constitutional manner."

The Supreme Court did not give reasons for the stay or say who voted for or against it, but an earlier Court statement said that two of the court's conservative justices, Antonin Scalia and Samuel Alito, opposed staying the execution.

Five votes of the seven top US justices must approve a stay of execution for it to be enacted.

Berry was on death row for killing a woman in 1987.