The Egyptian army has used force to disperse activists gathered in Cairo’s Tahrir Square to demand the removal of Hosni Mubarak loyalists from the interim cabinet.
Egyptian soldiers fired in the air and used batons in the early hours of Saturday to disperse the crowd, the Reuters news agency reported.
Demonstrators had also gathered in front of the parliament building in Cairo, where police beat protesters and used tasers to suppress the crowds, an Al Jazeera producer in the capital reported.
The Supreme Council of the Armed Forces, the ruling military council, later apologised for the military's response and said the situation "wasn't intentional".
In a statement, the council promised such confrontations would not happen again.
The people had gathered to celebrate two weeks since the removal of Mubarak from power and remind the country's new rulers of their promise to guard against a "counter-revolution" of the people's power.
After midnight, when a curfew goes into effect, military police moved in to clear them away and beat protesters, some of whom tried to resist, according to Shady Ghazali, a leading youth activist who said he witnessed the clash.
One man was slapped so hard he bled from his face," Ghazali said.
He and at least four others were detained and taken to a lock-up that already held dozens of other protesters who were apparently arrested throughout the day, he said.
Some of them showed bruises and other signs of mistreatment, he said.