The opposition Muslim Brotherhood have won a record 19% of seats in Egypt's three-round parliamentary elections, preliminary results say.
Police blocked access to several polling stations on Wednesday
President Hosni Mubarak's ruling National Democratic Party won over 70% of seats, giving it an important two-thirds majority.
The results in some constituencies are yet to be announced and 12 seats will be contested in further run-offs.
Eight opposition activists were killed in violence on Wednesday.
The Egyptian Organisation for Human Rights said the deaths came during "clashes with security forces which cordoned off polling stations to prevent voters from voting".
Interior ministry spokesman Ibrahim Hammad said Muslim Brotherhood "thugs" were behind the disturbances at 10 polling stations.
Eleven people have now died since the election began on 9 November.
The US has criticised the conduct of the poll, saying it sends the wrong signal about Egypt's commitment to reform.
The banned Muslim Brotherhood, whose candidates stood as independents, won 11 seats in Wednesday's run-off, while the NDP took 111.
Egypt's oldest and largest Islamist organisation
Founded by Hasan al-Banna in 1928
Group has influenced Islamist movements worldwide
Mixes political activism with charity work
Banned from open political activity
Rejects the use of violence and supports democratic principles
Wants to create a state governed by Islamic law
Slogan: "Islam is the Solution"
The brotherhood will now have a record 87 seats in the 454-strong People's Assembly, almost six times the number it had before.
The Islamists believe they were entitled to more seats and say that rigging and intimidation led to their being beaten in some constituencies.
With the results from some constituencies to be announced later, and seven candidates standing in run-offs, the group may make further gains.
The ruling NDP won at least 314 seats, significantly less than the 404 seats it gained in 2000.
But it has maintained its crucial two-thirds parliamentary majority required to pass constitutional amendments.
The BBC's correspondent in Cairo, Heba Saleh, says the Egyptian authorities have always argued that a party based on religion would deepen sectarian divisions in a country with a sizeable Christian minority.
But with the Muslim Brotherhood now confirmed as the largest opposition force in the People's Assembly, the government must now deal with a party banned from open political activity.
The signs so far, are that the government will continue to resist giving the Brotherhood any form of legal status such as allowing them to become a political party, our correspondent says.
But with almost a fifth of the seats in parliament occupied by Muslim Brothers, the government might find it difficult to continue to arrest members and leaders of the group, on charges of belonging to an illegal organisation, she adds.
The dilemma for the government now, is that if it continues to harass the brotherhood, it will alienate many Egyptians and if it lifts restrictions on them, it could watch them make even more gains.