Egyptian protesters and police have clashed in Cairo ahead of a massive rally by opponents of Islamist president Mohammed Morsi demanding he rescinds decrees that granted him near-absolute powers.
They took place near the US Embassy and the Egyptian capital's Tahrir square - birthplace of the uprising that toppled president Hosni Mubarak's regime nearly two years ago.
Police fired tear gas after hundreds of protesters pelted them with rocks in a street leading off the square toward the embassy.
The protesters have been staging a sit-in at the square since Friday to demand Mr Morsi revoke his autocratic decrees.
Mr Morsi, in power since June, says the decrees are necessary to protect the "revolution" and the nation's transition to democratic rule.