Egyptians gathered in Cairo's Tahrir Square today after a week of demonstrations, to tell the ruling generals they are failing to meet demands to reform the system.
But the Muslim Brotherhood, Egypt's most organised group, said it was not participating and said the authorities must have time to respond to demands first made at a mass rally last week.
The split partly reflects caution in the Brotherhood, banned under ousted President Hosni Mubarak, about upsetting the army under which it now has unprecedented freedom.
Analysts said it also indicates the gap between the Brotherhood's cautious approach and a new generation of activists, who are less well established but determined to keep up the pressure.
"The youth reject the language of threats used by the Supreme Council [for the Armed Forces], and reject that this is the way for dialogue," said Mohamed Adel of the April 6th movement, which has been calling for a big turnout on Friday.
Hundreds of demonstrators gathered in Cairo and Alexandria today by noon prayers. Numbers tend to climb after prayers, when the summer heat cools in the afternoon and evening.
Activists, some of whom have camped in the square for a week sheltering under canopies from the scorching sun, were angered by the tone of an army statement this week that suggested protests were threatening public order.
At a news conference, generals defended the use of military courts saying they had not been used to stifle opinion but only against serious crimes. The army also said it would use all legal means to end the protest without resorting to violence.
But there has been no sign of any action to stop the protest in Cairo or in other cities where demonstrators have rallied.
The army has also said it backed the prime minister, Essam Sharaf, who is working on a cabinet reshuffle. Other concessions include a shake up of hundreds of senior officers in the police, a force scorned for violent tactics used under Mr Mubarak.
"Purging all state institutions and particularly the judiciary," is one of the demands listed by April 6h.
The movement and others have named officials still in place that it wants fired. They have also demanded that military courts, long used by Mr Mubarak, should not be used for civilians.
Reuters