Youths have clashed with police in Cairo as protests at new powers assumed by President Mohamed Mursi stretched into a second day, confronting Egypt with a crisis that has exposed the split between newly empowered Islamists and their opponents.

A handful of hardcore activists battled riot police in the streets near Tahrir Square, where several thousand protesters massed on Friday to demonstrate against a decree that has rallied opposition ranks against Mursi.

Mursi's critics have called for a big protest on Tuesday.