Inmates have beaten a Frenchman to death during a quarrel inside a detention center in the Egyptian capital, Cairo, Egyptian security sources say.

“There was a fight between him and six other detainees (inside a cell in the Qasr al-Nil police station) when he wanted to turn the light on while they wanted it off to go to sleep. They attacked him and he had a brain hemorrhage and died (on Sunday),” the source said, on condition of anonymity, on Tuesday.

However, French Foreign Ministry deputy spokesman Vincent Floreani said the man was killed on Friday.

The French ministry urged the Egyptian interim government to launch an investigation into the death.

The man, who was reportedly a teacher, had been detained in Zamalek neighborhood of Cairo for allegedly breaking a curfew imposed by the military earlier this month.

Egypt is still witnessing near daily protests demanding the reinstatement of the ousted president Mohamed Morsi.

About 1,000 people were killed in a week of violence between Morsi supporters and security forces after police dispersed their protest camps in a deadly operation on August 14.

The massacre sparked international condemnation and prompted world bodies to call for an independent investigation into the violence.