South Carolina is officially using the firing squad as a method of execution. File pic

South Carolina has brought back the firing squad as a method of execution, making it one of the few US states where it is lawful to carry out a death sentence in that manner.

According to the state Department of Corrections, it will be possible for inmates on death row to choose to be shot among three execution options.

They will be allowed to decide whether to die by lethal injection, death by a firing squad of three men with rifles, or the electric chair.

The US - alongside the likes of Iran, Egypt, and Saudi Arabia - is one of the few countries that still permits capital punishment. It and Japan are the only G7 countries to do so.

Many states in the US do not permit capital punishment.

South Carolina, Mississippi, Oklahoma, and Utah are the four states in the US that allow firing squad executions.

Three inmates in Utah have been executed by firing squad since 1977, according to the Death Penalty Information Center (DPIC).

The death penalty was reintroduced in the US in 1977 following a 10-year pause, during which the Supreme Court attempted to address the legal questions around the issue.

According to the DPIC, at least 186 people who have been sentenced to death in the US were later exonerated as a result of improper convictions, 100 of whom were black.

The last person in the US to be executed by firing squad was Ronnie Lee Gardner in 2010, a 49-year-old who killed a man while attempting to escape from a courthouse in 1985.

South Carolina's last execution was in 2011, of 36-year-old Jeffrey Motts who was put to death by lethal injection for murdering a cellmate in 2005.

The US reinstated the death penalty in 1977 since when more than 1,540 people have been executed. More than a third of these executions, 575, have been in Texas, while 43 have been in South Carolina.

There are currently 35 inmates on death row in the state.

According to a press release, the death chamber at the state's prison has been updated with a firing squad metal chair, as well as protective equipment and bullet-resistant glass to separate the witness room.

The release said the firing squad members would be volunteer correctional employees who must meet specified qualifications.