Egypt's opposition Muslim Brotherhood won more seats than the ruling party in the second round of parliamentary elections on Sunday.
Islamist supporters say many were stopped from voting
Independents standing on behalf of the banned group won 13 seats, while the National Democratic Party secured only eight. One went to a Nasserite party.
But there will be run-offs for the remaining 122 seats on Saturday.
The NDP won most seats in the first round and is expected to maintain its majority in parliament.
Sunday's vote was marred by minor violence and civil society groups speak of widespread intimidation and voting irregularities.
Independent candidates allied to the brotherhood have now won 47 seats in the first two rounds of the election, compared with 15 in the outgoing parliament.
The results mean the group has scored its biggest electoral victory ever, and will become the largest opposition force in the People's Assembly.
BBC Arab affairs analyst Magdi Abdelhadi says the result is a blow to President Hosni Mubarak's NDP which, though backed by the huge resources of the state, has failed to secure an outright victory in most constituencies.
The brotherhood's success will also increase the pressure on the state to either accommodate it within the existing legal system or change the law, which bans religious political parties, our correspondent says.
Shortly after the declaration of the official results on Tuesday, police released more than half of the 460 Muslim Brotherhood activists detained before and during the poll.
There were clashes on Sunday between Islamists and supporters of the NDP.
"About 260 have got out and there are still about 200 [in prison]," Issam al-Aryan told Reuters.
Egypt is electing 454 members of parliament in three stages. The last round is scheduled to be held on 1 December.