Protesters gathered briefly near Egypt's parliament building
Baton-wielding Egyptian police have broken up a pro-democracy demonstration in Cairo.
They beat protesters and dragged dozens away from outside the upper house of Parliament, taking them away in trucks before reportedly releasing them later.
Demonstrations are illegal under Egypt's stern "emergency laws", which have been in place for 30 years.
The protesters were calling for a change to the constitution that they say would make elections more fair.
The demonstration was called by the 6 April youth movement, which backs the presidential candidacy of Mohamed ElBaradei, the former head of the United Nations' nuclear watchdog.
"It's an insulting image for Egypt," opposition politician Ayman Nour told reporters.
"Hundreds of soldiers are denying the right of a few dozen civilians trying to express their desire to amend the constitution."
Mr ElBaradei was not at the demonstration but he has said he would run in elections planned for next year if there were changes made to the constitution allowing fairer polls.
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Opposition parties are in effect banned by the government's use of the tight restrictions on the political process in the Egyptian constitution.
Journalists covering the protest were also beaten with police batons, and photographers' cameras confiscated.
The 6 April movement was formed in 2008 through the social networking site Facebook.
The group campaigns for political reform through a series of strikes and has over 70,000 members.
Mr ElBaradei, 67, has hinted he may stand against 81-year-old President Hosni Mubarak, who has ruled since 1981, in an election due in 2011.
Observers believe President Mubarak wants his son Gamal to succeed him.
Analysts say Mr ElBaradei's appeal for many Egyptians is that he is a civilian in a country long ruled by soldiers, and that he is untainted by corruption allegations.
But detractors writing in state media have portrayed him as a figure who is out of touch with Egyptian life, having lived abroad for so many years.