The spiritual leader of the Muslim Brotherhood, General Guide Mohammed Badie, has been arrested in Cairo according to Egypt authorities.

Reports said he was detained at a residential flat in Nasr City.

A state of emergency is in force in Egypt amid turmoil following a crackdown on Islamists in which hundreds have died.

A three-day period of mourning has been declared for 25 policemen killed in the Sinai peninsula by suspected Islamists.

And 36 Islamist protesters died in a prison van in the capital Cairo on Sunday.

Almost 900 people, including more than 100 police and soldiers, are reported to have been killed in Egypt since Wednesday, when the army cleared protest camps set up by supporters of deposed President Mohammed Morsi, many of them members of the Muslim Brotherhood movement.