Supporters of Egypt's President, Mohammed Mursi, have clashed with opponents in Cairo's Tahrir Square, leaving more than 100 injured in the worst violence over the Islamists' leadership.

Mr Mursi's Muslim Brotherhood movement and a coalition of secular-leaning groups held separate rallies on Friday on some of the thorniest issues facing the new democracy.

Bitter division ... an anti-Muslim Brotherhood protester weeps as another prepares to throw stones at rivals. Credit:AFP

The Health Ministry said at least 110 people were injured as protesters showered each other with stones and petrol bombs, after Mr Mursi's supporters tore down a podium from which anti-Brotherhood chants were being orchestrated.

Protesters torched two buses used by the Brotherhood to drive supporters into central Cairo, witnesses said.