LITTLE ROCK — After nearly a dozen years without an execution, Arkansas is racing to put eight men to death next month over a 10-day period — an unprecedented timetable the state says is necessary because one of the three ingredients in the lethal injection will soon expire.

If carried out, the executions beginning April 17 would make Arkansas the first state to execute that many inmates in such a short time since the death penalty was reinstated by the US Supreme Court in 1976.

The accelerated schedule calls for prison staff to conduct four double executions, with only a few days in between. It poses a number of risks, experts say, and the state’s preparations are shrouded in secrecy.

Some attorneys and death penalty foes question whether the quick turnarounds will intensify pressure on the prison staff and cause problems.

An investigation in Oklahoma found that intravenous lines had been connected improperly, in part because of the ‘‘extra stress’’ from the state’s scheduling of two executions on the same day.

‘‘The stress on the prison and medical staff will be increased, and the risk of making mistakes is multiplied,’’ said Dale Baich, an assistant federal public defender.

On Monday, the inmates asked the US Supreme Court to reconsider its decision to not review a ruling upholding the lethal-injection law.

Associated Press