Al-Qaeda chief's brother arrested in Egypt

The brother of al-Qaeda chief Ayman al-Zawahri has been arrested in Egypt, an official says.

Egyptian authorities have arrested the brother of al-Qaeda chief Ayman al-Zawahri, a security official says.

He said Mohammed al-Zawahri, leader of the ultra-conservative Jihadi Salafist group, was detained at a checkpoint in Giza, the city across the Nile from Cairo.

Mohammed al-Zawahri's group espouses a hard-line ideology but was not clandestine prior to Egypt's July 3 coup.

He was allied with ousted President Mohammed Morsi, an Islamist, whose supporters are now taking to the streets to protest the killings of its supporters in a security crackdown last week.

The official declined to give further details. He spoke anonymously as he was not authorised to talk to the press.

Authorities said earlier that al-Zawahri had commanded insurgents in the Sinai Peninsula.

An anti-military coalition led by Morsi's Muslim Brotherhood has called for a week of protests, further escalating unrest in the country. The coalition says that they won't back down until it topples the government installed by the military.