Egypt's military arrested hundreds of protesters yesterday and said that at least 300 would be held for 15 days while prosecutors investigate their role in "attacking troops and disrupting public order."
The detainees are said to include 15 journalists.
The arrests followed massive demonstrations against the ruling junta on Friday, which turned violent after activists attempted to break through the barbed wire fences of the Defence Ministry.
Soldiers and police responded with water cannon, tear gas and live ammunition, injuring hundreds.
One soldier was said to have been killed in the clashes and two detainees are being questioned in connection with the incident.
Military general prosecutor Adel el-Morsi ordered the release of all women protesters who were rounded up, though he did not explain why.
Egypt's military has previously been embarrassed by revelations of brutality towards women and accusations of conducting humiliating "virginity tests" on female detainees.
The rally outside the ministry was called in response to the deaths of nine anti-army protesters on Wednesday when a sit-down protest was attacked by supporters of the junta.
The Muslim Brotherhood accused authorities of double standards today, saying it was "astonishing and surprising" that they were moving so quickly to prosecute those who attacked their headquarters but had made little effort to track those who started Wednesday's violence.
Media reports blamed Islamists for Friday's violence, though the crowds also included secular protesters against the continued rule of the Supreme Council of the Armed Forces headed by ex-despot Hosni Mubarak's army chief Field Marshal Hussein Tantawi.
Tension among both secular and Islamist organisations has risen in recent weeks as the electoral commission has disqualified several presidential candidates on technical grounds.
This has led to accusations that it is smoothing the way for a candidate favoured by the generals.
Muslim Brotherhood candidate Khairat al-Shater, whose removal from the list due to a Mubarak-era criminal conviction caused outrage among Islamists, had been rated as the frontrunner.
The army dismissed claims today that it was seeking to delay or influence the transition of power to a civilian administration.
It said in a statement that its "mission" would be over as soon as a president was elected - on July 1 at the latest by the current timetable.
Nothing will bring back the hundreds of British soldiers killed fighting in Iraq at Tony Blair's behest.
Under a modicum of scrutiny the PM's international 'achievements' quickly unravel
The Con-Dems have had it their way too long. We have to turn this country around