Scuffles and stone-throwing broke out in Cairo's Tahrir Square hours before Sami Enan, Egypt's military chief of staff, met political party leaders a day after protesters in the square demanded reforms.
Enan, who is also the number two in the ruling Supreme Council of the Armed Forces (SCAF), invited a range of parties - including the Muslim Brotherhood and the liberal Wafd to talk, the state-owned Al-Ahram newspaper reported.
During the meeting, the parties called for the abolition of a controversial article in Egypt's new electoral law, and for a ban on former regime members running for public office.
Saturday's meeting comes a day after thousands flocked to Tahrir to demand an end to military trials of civilians and cleansing institutions of remnants of Mubarak-era officials.
Trouble broke out on Saturday when protesters who said they would stay in the square until their demands were met were forcibly removed by security forces and troops.
Some of the demonstrators who refused to move began hurling stones at riot police, who were carrying shields and batons.
Al Jazeera's Rawya Rageh, reporting from Cairo, said 10 people were arrested, none of whom "belong to any of the known grassroots movements".
Most of the main groups involved in Friday's rally had said they would not take part in Saturday's sit-in.
'End to emergency law'
Around a dozen protesters had been arrested on Friday after around 300 tried to head to the defence ministry but were blocked by military police.
"We are planning to hold a big sit-in as we have three demands, an end to emergency law, an end to military trials of civilians and speeding up trials of previous top officials," Mostafa el Hag, a 28 year-old singer and activist said.
"We are waiting to see what the military council says on Sunday," he said.
On Tuesday, SCAF laid out the timetable for the first post-Mubarak elections, which will start on November 28 and take place over four months. A presidential election is also expected to be held next year.
The Democratic Coalition, which groups dozens of parties such as the Muslim Brotherhood and Wafd, has threatened to boycott the vote, fearing that the new electoral law will help old regime figures to return to parliament.
SCAF has been in power since president Hosni Mubarak was ousted by a popular uprising in February, and has repeatedly stressed its commitment to democracy.
But protesters have been gathering in Tahrir on an almost weekly basis to express their anger and frustration at the military's handling of the transition.
Under Mubarak, candidates affiliated with his party used patronage or pressure to garner votes.
Activists say that a proportional list system would help avoid that, because voters would be electing candidates based on a party's political platform, circumventing candidates' personal power and influence.