"Drag me, strip me, my brothers' blood will cover me!" they chanted. "Where is the field marshal?" they demanded, referring to Mohamed Hussein Tantawi, the head of the military council holding power here. "The girls of Egypt are here."
The event may have been the biggest women's demonstration in Egypt's history. Previous attempts to organize women's events in Tahrir Square this year have either fizzled or, in at least one case, ended in the physical harassment of the handful of women who did turn out.
The women's chants were evidently heard at military headquarters as well. On Tuesday evening, the ruling military council offered an abrupt apology.
"The Supreme Council of the Armed Forces expresses its utmost sorrow for the great women of Egypt, for the violations that took place during the recent events," the council said in a statement. "It stresses its great appreciation for the women of Egypt and for their right to protest and to actively, positively participate in political life on the path of democratic transition."
Although no one in the military has been publicly investigated or charged in connection with any misconduct, the statement asserted that the council had already taken "all the legal actions to hold whoever is responsible accountable."
On the fifth of day of clashes between demonstrators and military police, the outpouring of women represented a stark shift for a protest movement that has often seemed to degenerate to crowds of young men trading volleys of rocks with riot police. It comes at a moment when many protesters were beginning to despair that they were losing a propaganda war against the military rulers' attempts to portray them as vandals and arsonists.