Updated

ALEXANDRIA, Egypt -- Protesters set fire to cars, tires and two polling stations, clashing with police firing tear gas in riots that erupted around Egypt on Monday over allegations the ruling party carried out widespread fraud to sweep parliamentary elections.

The country's most powerful opposition movement, the Islamic fundamentalist Muslim Brotherhood, acknowledged that its lawmakers may be all but completely swept out of parliament by what it and other called rampant rigging.

That's a significant blow to the group, which held 88 seats -- a fifth -- of the outgoing parliament, and it is widely believed that it was the government goal to drive out its only real rival's lawmakers. The election showed the Brotherhood's limited options after repeated crackdowns in past years -- including the arrest of some 1,400 of its activists in the weeks ahead of the vote.

Brotherhood figures admitted they could do little to stop vote rigging, fearing that protests could make their movement appear violent and bring a harsher crackdown amid uncertain political times.

"We were very restrained and were given instructions from up top to be extremely restrained," said Sobhi Saleh, a Muslim Brotherhood candidate in the Mediterranean coastal city of Alexandria. "We want to show the world that we are not thugs, we will not resort to violence."

Sunday's parliamentary vote was overshadowed by a presidential election set for next year, which is clouded in uncertainty because the man who has ruled Egypt for nearly three decades, 82-year-old President Hosni Mubarak, has had health issues and underwent surgery earlier this year. Many believe Mubarak is positioning his son, Gamal, to succeed him, but there is widespread public opposition to any "inheritance" of power.

Saleh said the Brotherhood was hoping that over the long term the rigging would discredit the ruling National Democratic Party in the public eye and draw people to the movement.

"We have a vision. There is no doubt we will have a new president in the next two years at least. Either Hosni who is ill, or his son -- who is disliked," he said. "When I lose seats this time, I will gain sympathy on the street. People know these elections were rigged."

A coalition of local and international rights groups Monday reported that the balloting was marred by widespread rigging after the government prevented monitoring. It said opposition candidate representatives and independent monitors who were supposed to be allowed to watch the voting were barred from almost all polling stations around the country, allowing officials to stuff ballot boxes.

Though official results are not due until Tuesday, candidate supporters around the country took to the streets in anger after hearing word their favorites lost.

In the southern province of Assiut, police fired tear gas at a procession of Muslim Brotherhood supporters armed with sticks who were carrying their candidate Mahmoud Helmi and chanting "Islam is the winner."

But in most other places, it was backers of independent candidates who rioted, or even of ruling party candidates defeated by rivals within the party. Further south in the city of Luxor, protesters set fire to cars and clashed with security forces. Five people were injured and 30 arrested.

Other protests erupted in Egypt's northern Delta region. Around 500 backers of the secular opposition Wafd party clashed with ruling party supporters in Gharbiya, and police fired into the air and shot tear gas to disperse them. Other protesters set fire to two schools used as polling stations in Menoufiya and burned tires outside a station south of the Mediterranean coastal city of Alexandria, briefly blocking the main highway to Cairo.

In a statement, the High Election Commission dismissed reports of violence or irregularities during the voting, saying that the few incidents it uncovered "did not undermine the electoral process as a whole."

The ruling party secretary-general, Safwat el-Sherif, blamed the Brotherhood for fomenting reports of fraud.

"An outlawed group of people is trying to stifle the positive results of the elections by spreading rumors about the whole process," he said, referring to the Brotherhood.

The Brotherhood's media official, Abdel-Galil el-Sharnoubi, acknowledged that when the results are announced, his movement may end up with almost no seats. He said none of its 130 candidates have so far secured a seat, either losing to the National Democratic Party or facing a Dec. 5 runoff. The Brotherhood website said that so far 27 candidates were going into the second round.

"The elections revealed the real intention of the regime to unilaterally take over the Egyptian political arena," el-Sharnoubi said.

Still, the Brotherhood rank-and-file clearly had the message from its leadership not to enflame the street, with the government highly sensitive ahead of next year's presidential vote.

"We are going through a period which we don't know where it takes us," said Mohammed Abdel-Fattah, a 35-year old lawyer and supporter of the Brotherhood in Cairo. "Any move must be calculated according to the political conditions in the country and the group's rules."

The coalition of rights groups estimated turnout Sunday was only 10 to 15 percent, substantially less than the 25 percent turnout in the 2005. While the government has yet to issue official figures, election commission chief al-Sayyed Abdel-Aziz Omar admitted it was "less than the accepted level."

Before the election, Egypt publicly rebuffed U.S. calls for international election monitors, maintaining that its own civil society groups were adequate to the task. The rights coalition, however, said authorities then largely prevented even local groups from watching.

In 2000 and 2005 voting, independent judges watched the polls, but a 2007 constitutional amendment also removed them.

"We are facing violations that we have not seen in the last two elections, when the stuffing of ballot boxes had stopped because judges were in the polling stations," explained Hafez Abu Saada of the Egyptian Organization of Human Rights. "This year we have gone back to the tradition of marking ballots."