|Amnesty International said there have been eight deaths related to the polls [Reuters]
The Muslim Brotherhood and a secular party, Wafd, have both withdrawn from Egypt's election after a crushing first-round defeat by the president's ruling party in a poll marred by alleged fraud and violence.
The main opposition party will boycott the second stage of parliamentary voting after a first round that critics said was rigged in favour of the ruling party, a Muslim Brotherhood source said on Wednesday.
The Wafd party, which controls the second biggest opposition bloc in the outgoing parliament, said on Thursday that it had withdrawn backing for two seats won in the first round of elections which it said was rigged.
"Sunday was marked by fraud, terrorism and violence carried out by police and thugs," the Muslim Brotherhood said in a statement, adding "the Brotherhood refuses to react to such violence."
Despite the boycott, "We still plan to take all legal measures to invalidate this pseudo-parliament," they said.
Essam El-Erian, spokesman for the Muslim Brotherhood, said that his party participated in the elections in the national interest and then pulled out in the national interest.
"I think public opinion accepted our decision, and they congratulated us for our historical decision," El-Erian said.
"[The Brotherhood] doesn't attribute the results to bad policies or bad campaigning," Al Jazeera's Ayman Mohyeldin, reporting from Cairo, said of the Brotherhood's accusations against Hosni Mubarak's party.
But our correspondent also said that most of the voters who supported opposition candidates were not surprised by the decision to withdraw from the second round. Moreover, he said many Egyptians had hoped the Brotherhood would boycott the elections even before the first round.
"We are looking at an incoming parliment that will be beyond dominated by the National Democratic Party," he said.
"There is concern as to whether it has simply become a rubber-stamp parliament and what that means for determining the future leadership of the country."
Egypt's ruling party captured nearly all seats in parliament in the first round of the disputed elections, according to official results.
The National Democratic Party won 209 of 221 seats in Sunday's polls, but the Muslim Brotherhood, the country's largest opposition group, failed to win a single seat.
The Muslim Brotherhood is outlawed in Egypt under a ban on religious parties and fields candidates as independents.
Fraud claims rejected
But the electoral commission dismissed the Brotherhood's claim that the vote was "rigged and invalid".
"The commission categorically rejects the allegations that the election was marred by fraud," Sameh el-Kashef, a commission spokesman, told a news conference.
"While the commission regrets that certain irregularities took place, it is satisfied with the fact that these irregularities did not impact on the transparency of the first round of the election."
Kashef said that only 1,053 ballot boxes out of 89,588 had been discarded and put turnout at 35 per cent.
Hafez Abu Saada, the head of the Egyptian Organisation for Human Rights, said voter turn out was no more than 15 per cent.
Four small legal opposition parties won five seats between them, and seven went to independents who are not affiliated with the Brotherhood.
Analysts said the government wants to push the Brotherhood to the margins of formal politics before next year's presidential race.
The group won a fifth of the seats in parliament in the last election in 2005, but a sustained government crackdown has since weakened the group.
Al Jazeera's Ayman Mohyeldin said that the Bush administration played a much stronger role than the current US administration in pressuring the Egyptian government to hold free and fair elections.
But the White House and US state department and have criticised how the poll was conducted.
"We are disappointed by reports in the pre-election period of disruption of campaign activities of opposition candidates and arrests of their supporters, as well as denial of access to the media for some opposition voices," Philip Crowley, the state department spokesman, said on Monday.
"We are also dismayed by reports of election-day interference and intimidation by security forces."
The Egyptian foreign ministry spokesman on Wednesday dismissed the criticism from the US as "unacceptable interference in Egypt's internal affairs".
The spokesman urged the Americans to "be more objective and careful in their stances and reactions, in order not to give a chance to those who want to harm the strong ties between the two countries."
Amnesty International said there had been eight election-related deaths and scores of injuries, mostly during clashes between rival parties.