Egypt's ruling Muslim Brotherhood said its Cairo headquarters came under attack this evening from scores of anti-government protesters firing shotguns and throwing petrol bombs and rocks.

The attack came amid mass protests across Egypt calling for Islamist President Mohamed Mursi to resign.

Brotherhood spokesman Gehad El-Haddad said he was in contact by telephone with staff at the compound, who told him its fortified perimeter had not been penetrated. Several provincial offices of the movement have been attacked in recent days.

Two men including an American bystander were killed when the Brotherhood's office in Alexandria, Egypt's second city, was attacked on Friday and dozens were wounded. The office was torched and ransacked.