An 11-year-old boy has reportedly shot his grandmother dead for ordering him to clean up his room.

According to reports, the incident happened in Litchfield, Arizona, USA on Saturday.

Sgt Joaquin Enriquez of the Maricopa County Sheriff’s Office said Doyle Herbert and his wife Yvonne Woodard had asked the boy numerous times to clean his room but he was “being stubborn about it”.

Around 5pm, when the couple were watching TV, the boy came up behind them and shot his grandmother Yvonne in the back of the head.

Mr Herbet said he ran after the boy but then raced back to help his wife Yvonne, 65.

He then heard another gunshot and turned around and saw his grandson take a few steps back before falling to the ground.

The grandfather then retrieved the gun and called the emergency services, reports ABC.

The gun belonged to Mr Herbert, and the couple were the boy’s legal guardians and had full custody of him.

The Sheriff’s Office said there had been no signs the boy would harm himself or anyone else.

“In the preliminary stages of this investigation there had been no previous signs that the grandson might harm someone or himself and there was no cause for concern prior to this event,” MCSO said in a statement.